Toda is regarded as one of the best headers but isn't cheap, Tegiwa is a Toda replica and get's good reviews and is half the price, you will need to change the front anti roll bar for a JDM version to fit these manifolds though.
I don't know much on the Buddyclub tbh but the DC Sports is worth looking at, a mate has one on his DC5 and hasn't had any issues, you need engine mount inserts fitted with this though otherwise you will void the warranty although I think fitting the mounts is good practise when fitting a header to prevent cracking. Japspeed also do one which is a cheap option but also gets good reviews and decent gains. Remap as well though when fitting a header if you haven't already.
As for a catback I don't think they will make more power than if you buy a decent aftermarket product, reputable brands will have had more R&D with their product.
I previously had a custom catback made by Longlife, I've now swapped it and the quality difference is night and day, really glad I did because it was crap the way it was fitted too, plus my Fujitsubo definitely 'feels' better performance wise.
The plus point of going custom is that you get to choose, bore size, noise, tailpipes etc but go somewhere you know is good, personally I wasn't happy with Longlife.
I found for what I paid for a custom made catback I could have got a good branded one, and I would stick with a decent after market one now after my experience.
Noise wise, you will gain a fair bit of this when you change the header anyway but quiet systems would be, Fujitsubo, Toda, Mugen, Tegiwa, look for ones which are silenced.
Hope this helps.
