I thought about mentioning the BC 2.6 kit, but there are a couple issues. The foremost is that you'd need custom pistons, as the kit generally would come with low compression turbo pistons. The second is that the rod ratio is pretty lousy - even worse than the 2.3/2.4L (1.41 - worse than a lot of domestics - your rev limit will somewhat limited, and the engine will have a hard time breathing without the turbo). The third is $$ - how much are you actually looking to spend and what are you building the engine to do? Also, the kit is only for 7-bolts.
As far as cams go, you'll probably want to mix and match. N/A engines typically have longer intake durations than turbo cams, with more overlap, but you don't necessarily want as much lift. (I'm imagining something like matching an HKS 272 intake with a 264 or stock exhaust cam, or maybe a 280/272. Unfortunately, many cam manufacturers for imports have adopted the "264, 272, 280" duration designations for every application, but the lift and duration at .050" are completely different. It might even be useful to mix brands between intake and exhaust to get the lift you want. I'd recommend looking at the detailed cam specs for various 1.8-2.5L engines out there. Don't start comparing things to VTEC cams though, as they can get away with much longer durations on the high lift lobe.
That still doesn't tell the whole story though, as bore/stroke vary, as do valve diameters. You can also play with relative valve diameter if you're getting head work done.
Intake and intake manifold and exhaust header design and resonance become more important than in a turbo application as well. Obviously you'll also want to either stick with the stock exhaust, or build one in the 2.25-2.5" diameter range. If you're doing a street engine using a 6-bolt, something like a cyclone manifold might be useful for getting some low end back. Otherwise, custom would be the way to go (or look for a sheetmetal intake with the smallest plenum size you can find).
The main question is, what are you going to do with it? Street or Race? 200 HP is probably pushing the limit of streetability for a 2.0L, maybe 230-250 for a 2.4L. More importantly, what kind of car are you going to put it in? A high HP, high revving N/A 4 banger works in a light car that doesn't take much to get moving. The galant is not a light car, and the lack of torque compared to a turbo setup will cause "issues" getting off the line in a highly tuned engine. It might be helpful to swap to a JDM final drive on the transmission and rear end if you plan to make your power higher in the rpm band.
I think my choice for an all out N/A engine would probably be a long rod 2.4L, or a destroked 2.1L for a race engine - You're trying to pump as much air as possible to get power. For a street car with a more reasonable budget, a 2.3L or standard 2.4L would probably do the job, or just stick with the 2.0L and focus on getting everything else to match up.
Pistons you might want around 11:1 for the street (maybe between 12:1 and 13:1 if you plan to run premium, depending on what octane you can get), or higher for race gas. Picking a CR is more important, as you can't simply make up the difference by raising boost pressure, only timing. Find the lightest components you can, especially rods, as they won't be seeing nearly the compression loads that a turbo engine will. Using a 7 bolt block might help in this instance.
Do your research and look what N/A tuners do with other engines.