1) Yes by far im saying look at all the k parts i had to get, plus youre doing k24 so you need the RBC and a rsx or equivalent throttle body, plus I forgot the shift linkage and shifter plate, etc etc no way could I feel its worth it unless you "just want a K" or insist you want NA.
2) My aforementioned b16 setup has the 28RS, best street turbo ever invented, but guess what, the CHRA is bad now and its 800 US to get a new one (almost the cost of the whole turbo new) which is why I recommend the 28R because of local availability and price, ball bearings are nice until they fail they you want to shoot yourself when what should've been a 100 US rebuild is a 800 US rebuild.The only other real choice would be a BW S252 close to the same spool, no water cooling, cheaper rebuild, supports more HP or the gt2871, these would give you the drag more hp advantage that you feel you want. While the surfer is a great turbo its overkill for you're power levels.
3) Dont stress the 11:1, if you feel you have shitty 91 have you considered water/meth tapped from the windshield washer tank? I take it you can get the blue windshield washer fluid anywhere in TT? (US 10 a CASE up here) for all the headache you're talking about you could just get a nozzle and a controller for a couple hundred US and plumb it into the intake tract..
4) forget looks, log beats ram at your HP levels any day because of less heat loss and pulse modulation, youre not shooting for 500WHp!
1) decide that its really 300 whp ish you want, at least for now
2) get a 28R from whoever upgraded their s15, 30 mins to swap out if it goes bad anyhow
3) sell the peakboost, log is better for youre setup and a t3 flange wont work anyhow (this sale is going to fund the rest of the project!) Also where is the AC fitting with the peakboost??
4) sell the tial wastegate the 28R is internally gated, another resaon to leave out the peakboost (this sale is going to leave you with money left over after the project! buy beers!)
5) get a log or use a stock hf/vx manifold and weld on a t2 flange
6) Remember John Brown (guy who built the Aboud civic one seater) used to tune on 11:1 and high whp all day so dont be afraid
7) Try the water/meth if you need the safety, inexpensive and leaves your winshield cleannnn, its like driving around with over 100 OCTANE
Take my advice on at least this one thing, when your 11:1 spools that 28r at 3500 RPM and you get a near linear powerband from 3500 rpm to 8500 or 9000 rpm you are going to be walking around with a perpetual grin, even at auto X youll be in boost so often people are going to start to call you Guy Smiley.