Basically any D-Series manifold will fit all kinds of engines out of that particular family. Except D17s, those are "special" (aka the worst engines Honda ever made).
Got a 4-2-1 header myself that I bought when my car still had the stock D14 in it and it directly fit my D16Z9 without any modifications.
And I can attest to the rust concerns - my rear arches were pretty bad (but still manageable) when I got mine, the front corners where the fenders meet the sideskirts were rotten through and the rear corners are also slowly starting to bloom, as well.
Definitely make sure to check those spots when you've got the time!
Oh, and your distributor is probably going to die at some point. All of them do, it's kind of inevitable.
Do yourself a favor and don't get one of those repro units when it finally goes out - Blueprint and Yingzhen and whatnot units are all Chinesium garbage.
The only high-quality replacement I could find was one of those rather tacky sounding "Dragon Fire" units, but quality-wise they are pretty much OEM+, made in the US (not China), and even provide a stronger spark than the stock dizzys do.
Other than that, welcome to the club! :)