I'm not going to give a full VFAQ since this site exists already.
I bought mine at www.extremepsi.com for $96 shipped. Shipping was quick and they had both red and *black* in stock. I wanted black for my car. Kibo ordered his from http://www.suspension.com/mitsubishi.htm and they are only $72+shipping. They do weigh a little bit for shipping. Most DSM vendors have the red in stock as they are more common.
Here are some tips of the prothane motor mount install. I installed the complete kit. The motor mounts are both complete replacements, meaning timing belt and tranny mounts. The rear roll stop is a complete replacement and the front is an insert. The complete inserts are 3 pieces, 2 poly and one metal sleeve. The insert for the front is 2 pieces and is harder material than the other 3 mounts.
First a few notes about removing the inner "sleeve" on the complete replacement mounts. If you don't have a vice, good luck. It's pretty much a necessity. Once in a vice, be very careful not to squish the mount out of round, I took a sawzall and carefully cut out the majority of the rubber. Doesn't have to be all of it, just most of it. Then take the sawzall and very very carefully cut through the metal sleeve. When it's cut all the way though the sleeve will loosen and fall out. However in order to not cut into the mount at all I had to cut 2 slits almost all the way through. Then I used a screwdriver and folded the sleeve towards the center, cutting the finally 1/16" through the sleeve once it was higher than the mount. Now it will fall right out. Just grease up the new poly bushings and push them right in. Before I installed my bushings I sandblasted and repainted all the mounts. No more bubbling paint and surface rust.
Make sure you have 14mm and 17mm open end wrenches, sockets of various sizes (I used 3/8" and 1/2") and a torque wrench. A cheater bar and ratcheting box ends are nice too.
Timing Belt Mount
I chopped this mount right at the point you see in the picture. It saves weight, I don't have power steering and it makes like a crapload easier working in the front. This will be more important for me this winter. Do it at your own risk but it's been done by quite a few cars, even frequently driven ones without an issue. No other real tips here for tips for this one. Jack up the oil pan with a board under it just a little bit (don't need to crank it high), undo the bolts and it's out. By far the easiest one. Make sure to tighten all the other bolts first before the big bolt that goes through the mount. Use a torque wrench where you can reach. Most torque is in the 36ftlbs region but check for each bolt.
Support this mount just under the tranny lightly. This mount is darn big! It's also a piece of cake. 4 bolts are behind plugs in the passenger wheelwell. 2 bolts on the bell housing. One big bolt on the "rubber" part. Make sure to crack the rubber bolt loose, but not removed before you do anything. Tighten that bolt last when you are done. Nothing more here. I cut off a bracket I didn't need that was attached to this mount.
Front Roll Stop
After I did the first 2 mounts one at a time I removed both roll stops at once with the engine jacked up lightly under the tranny.
Onto the front mount. Haha have fun. This mount is a pita in some cases. There are 3 bolts only holding it in. However(!!!), if you have a down facing turbo it is too tight to get the mount and insert back in while just the mount slides out no problem. The solution is not too bad now that I figured it out while getting dirty and cursing for an hour. There is a large mount that bolts to the block and connects to this mount. 2 bolts hold it on, 17mm and not that hard to reach. Remove these bolts and this mount. Then squish the inserts into the rubber (it's obvious) and install small mount into big mount. Make the assembly as small as possible and don't worry if nothing lines up. Just make sure you can slide and rotate it to line up easily. Now with the intake pipe off, drop the assembly down into place. This takes lots and lots of manuvering and time to get right. You'll see when you're there but it is possible. The farther the turbo and elbow is from mount the easier it is. When you finally get it tighten the 2 bolts from the large block mount first, then the rear bolt loosely in place, then the front big bolt loosely in place then the front bolt. Tighten completely in the same order except swap the last 2. This is possible on a downpointing turbo but you have to take the big block mount off and it takes some time.
Rear Roll Stop
Now onto the last mount. I heard horror stories about this mount but it was just as easy as the first 2. It has 4 bolts total and with no AC and a magnus intake manifold they are very easy to get to. Hard to fit a socket on them but still not that hard with open end wrenches. If you have ac and stock IM then it might be harder.
Every single mount on my car was torn through so i'm sure this is much much better. Engine is in there solid now and it vibrates. I still have BS on this engine and I haven't driven it much yet. But it's going to buzz and now the motor will stay much more in place. Worth $100 to me and the install time even with the motor in the car. Would be even easier with the motor out. Hopefully wheelhop in the groove will be reduced. BTW I really dig the black and it's very stealth mod.
That's all I can think of. Ask questions away now before I forget how I did it!