What engines are compatible with a 2002 Honda Civic, LX trim?

The current engine is a 1.7L SOHC 4 Cyl. & it's not the stock engine either. I've been told by many that an important plug isn't attached. Doesn't really change the performance though. The reason I'm asking is because I was in an accident with snow, that broke my radiators. I got the cooling radiator replaced but the body shop mechanic did a bad job & added a sealant, that wasn't necessary. Now my current engine is throwing up the anti-freeze/coolant, after changing the radiator again as well as the cap & the thermostat & both sensors & it still overheats all the time. My good mechanic said he can get me a Japanese engine with 65k miles, labor & parts comes to 1,000$. I may take up on this since I can't get another car at the moment, I just don't know I his engine will reduce my cars performance & I don't want that. Any help is appreciated, please serious answers from mechanics or people who have done swaps themselves, thanks!

That sounds a little on the low side for where I live but you can check engine prices around you by calling local junk yards ebay shows prices from 350 on up depending on milage then you got shipping prob. Around 2-3 hundred as it goes by freight (tractor trailer) as for labor I'd guess that should run about 350-500 depending on the time it takes. I haven't done one lately so don't remember what the book gives and being Sunday I can't look it up