No, copper is definitely the way to go. You could use a pipe bender, but I've never seen one to do that.

I have to wonder what kind of pressure drop this thing has.

It definitely isn't meant to fit inside a case. That guy (in the link) has it right, by pinning it up on the wall.

Maybe airflow could be maximized by one of those radial fans, which would such air from the side, and blow it all over the pipes, ******ds...

yeah thats what i thought. well i just baught my pump today and im now currently building my res cause its a sub pump. iv been tghinking about the rad alot and mabey i think it would still be eaiser to go with the fridge rad. all i have to do is knock one off of an old broken down fridg and done. most of the work is done for me all i need to do is stick it in an enclosure and i have a rad. well at least thats my fealing on the situation now, have you guys got any better ideas?

I think for a homemade rad, many parallel tubes are the way to go, to avoid just such a pressure drop.
You could use the above coils, just cut them ito short segments and use a manifold on each end.

Round tubes suffer from laminar flow though, and it's hard to make sure you get good flow through ALL the tubes :shrug: . The best bet is very thin & wide flat tubes and turbulators(HC's tubes usualy zig~zag [in> \/\/\/\/\/\/ >out] to create turbulance) so that as many water molecules are in contact with the copper as is humanly possible without it being too restrictive. Then you have to add as much surface area (fins) as possible to those tubes for the air to 'force convect' the heat away from, round is'nt the best for surface area, in fact it's the worse :) ...

You can't beat a heatercore for size~performance~cost. If you're doing it for fun: Good! If you're looking for performance: Buy a HC...