B18 + Turbo. If you can find turbo parts and piece a kit together rather than buying a kit, you can make that budget.
Whoops. Didn't see that he had a 7th gen.. my b!no b's and h's only k's
if u really want to swap your engine to a k series your going to need at least 4-5 grand, and that just for parts, most the time these swap cost like 8-9 grand in the end, if u get it installed by a shop. but yeah good luck with the swap