200bhp is loads for the road I promise. If the car is stripped (ie light) you'll get it down to about 800kgs, so will have a very respectable power to weight ratio that'll really show up a huge range of "proper" cars
Roads that are really really good fun to drive down with 200bhp become almost undrivable at 300bhp. If its 200bhp or thereabouts, you can do that without going low comps but of course, you'll want more power once you've got the bug
As you've noticed, it's the incidentals that add up - brakes are just one part. go towards the 300bhp mark, and gearbox is another issue that'll see you £1000+ lighter.
A year ago, I'd have recommended the DP engineering setup, but after we had a problem with the exhaust manifold that we reported to DP they didn't fix it - I saw a brand new DP manifold just two weeks ago with the same fault. In our case, the fault was bad enough to rip a manifold stud out the head and caused us a lot of problems. The manifold IS good, but really - for 200bhp, a home made manifold is more than enough, even though it looks ugly
There's plenty of ways to keep the costs down from using a GT3 intercooler to using second hand clio injectors, etc etc. There's lots of ways, especially if you do most of the work yourself. There's a HUGE amount to be saved just in the management route too - you can go MF2 with a basic setup, but even if you go Omex or Emerald, you shouldn't be paying ANY more than £450 for mapping from start to finish.