R cams, be it ITR ot CTR are the “choice” stock upgardes for your b17.
of course the CTR or 01 ITR intake cam being the best. the Exhaust cam is basically the same thing. as for where to buy em… u can try all the web stores out there on the net, and compare prices.
for expected HP… it all dependent on how u tune it. (hope u already have cam gears) by just simply droping them in don’t expect an instant 8hp increase… NEVER works that way. onoly way to tell your gain is a dyno run b4 adn after the the install of the cams. HTH