Ive had a few s2k that Ive tracked. My current model if I were to buy another or giving advise:
ap1 9-13K depending on options that come with it 80-150k miles is fine as long as compression is tight and its a clean title straight chassis. Price gap reflects the milage more than anything. Don't be worried about hight mileage cars if leakdown numbers are good.
Ap2 05 only. has the 2.2 but is still drive by wire. which mean easier ECU mods if you want to do that. Your mostly paying for the updated trans internals and diff. cost around $12-18 mileage is same as ap1, as long as it all is within compression spec and chassis is straight.
Get either car ON A LIFT and have the mechanics look for signs of accidents, fender benders are ok but have alignment checked that it can be put back in spec and nothing is hugely bent. The chassis are stout so any perminate damage was likely a big hit.
Once you have the car:
Ap1:
front 22mm sway w endlinks
KW or Zeal suspension (probably others but i like both those for track)
17x9 +45 square set up
harddog roll bar
Seat and *5* point harnes
porterfield r4s pads and motul rbf 600 fluid.
CR chin spiler and CR or APR rear wing
I always left stock airbox but removed the resonator and usually kept stock exhaust. Its heavier but bullet proof if your going off track semi frequently.
your out the door for about 18k in a super reliable/safe/quick car. Mind you some people dont 'click' with s2000's, it take a certain type of driving to be fast.
heres one of my old cars. No wing with a mugen front and it was pretty quick on track. had a hard top for track use too..
Ive been doing research on the f20 motors again since one is going into my new build, Ive found some interesting things that are pretty simple to do to simplify the whole set up. rather than retype all them check out the build blog here:
http://illvillains.blogspot.com/