i look at it as a b16 vs b20vtec type of thing. the sr being the b16 making it more reliable to rev but the ka being more torquy and more of a bottom end type of thing but you sacrifice revving high not necessarily power up top. Stock for stock I would do a SR swap since it's stronger and boosted... Both in built form, I would do the KA. Iron block (stronger) and displacement will get you. if you tune both the sr and ka on the same psi under all the same circumstances, relative turbo size, etc.... the KA should make more power. no replacement for displacement. You will also spool the same size turbo quicker. It's all about preference and what you like and what feel you rather have... KA is underlooked in so many levels though. Idk why so many people are so clueless about it.

I recently went through this and wanted a sr20 until I did some research and decided to build the KA. Go on ka-t.org you will find useful information about turbo ka builds if you still have it as an option.