If you're concerned about overpaying for results, what can you tell us about how you use this car most often and your performance goals? Is this going to be your all-in, Hail Mary engine build? Is this just going to be another 400awhp, 10-second, daily driver "race car?" Not to be a dick, but there's a couple pretty heavy items on your list. If you're not 110% honest with yourself about how you're going to use the car, it's quite possible you'll dump a metric sh*t-ton of cash into this thing, start breaking weakest links, and burn out.
I dropped over $6K into a high-compression, 9000rpm screamer in my old Talon. It sounded sick. It was sick. But it had absolutely no balls whatsoever below 3500rpm, wanted to knock on Heaven's door all summer long, and I had all of zero interest in drag racing. For that kind of coin, I could have fully prepped a GVR4 for rally and entered my first event. Tough lesson to learn, my friend.
So, why are you looking at 280 cams and oversized valves? Being turbocharged, we're not as seriously affected by such things as the NA guys, but I'd be willing to bet money you'll lose low end grunt while increasing lag. What turbo are you running? Planning to max it out? How's your bottom end setup? Can it handle copious amounts of boost all the way to 7000rpm?
Just some food for thought. You seem like a thoughtful guy. Figured I'd throw it out there.
EDIT:
Just for comparison, I think my ideal street setup would be a mildly ported Cyclone intake side running +1mm, 5-angled valves, a couple Somender Singh gooves in the CC, 5-angled stock exhaust valves, a set of Evo VIII cams (262s?), a cleaned up FP cast manifold, and E316G running speed density.
That's pretty much what I want for the race car, too, although I think I'd probably leave the valve sizes alone, step up to either Kelford TX258 or FP1XX cams.
Oh, and I'd never piss away money on fancy pants premium head gaskets or timing belts. Not to say they don't have their uses, but I'm not pushing the engine that hard. Tune it within an inch of its life, then dial it back and leave a little something on the table. Ain't no fun JSB.
