good place for parts

I just had my 351 rebuilt for my 85 Supra Sunsport. I've heard its good to replace some of the other parts while you're at it. I also need to replace my exhaust manifolds. I was thinking I would just get them from my local marine shop, but they were beyond ridiculous. I believe in buying local, but just my manifolds were $260 ea from my local shop, $139 ea at glmmarine.com. Sorry, way to big of difference. So I was wondering where might be a good online source for exhaust manifold, water pump, fuel pump. anything else you'd recommend changing on the new engine?