you wont get 300whp from a stock 2.0L K-series engine block, but with bolt-ons I/H/E and Kpro tuned you could get anywhere from 210-230whp range, depending on which 2.0L engine you go with, diff bolt-ons, exhaust size, Kpro tune etc.
as for the the k20/k24 build I'm not sure, depends on your...