Advice on new Header(s) for Civic

Hi everyone I'm new to this board.

I have a couple of questions.

I recently discovered huge cracks in my stock exhaust manifold. I decided of course its not worth it to try to pay someone to repair by welding as they look in kinda bad shape. So I called honda and they said $285 for exhaust manifold stock. Holy crap! So I found some decent ones on ebay. Stainless steel Ractive header(s).

I was told the heatshield won't fit. Is there something I need to do? Do i need to paint the headers with some kind of paint to keep the heat down? So the paint doesn't bubble on hood? (for some reason my clear coat is bubbling on places but thats a diff issue )

OH and my car is 1993 Civic EX 1.6L. The seller told me its a bolt on job thats not to hard. Should I go ahead and have someone else install it? I can do things on car my dad and I replaced brushes on alternator and that kind of stuff.

I wasn't so much looking for performance gains. Just replacing the old header(s) (i could smell carbon monixide getting into cabin sometimes and smelled bad under hood and was hearing loud noises now).

My car is a driver. Not a racer. So will I have much problems on the highway with the headers or the heat?

Thanks for any info!! I appreciate it a lot!