Best choices for hookup wire?

Neotech copper.

A good solder connection is very important also.

'Hook Up Wire'? I sense you are not a serious audiophile.

It's only one connecting run in each amp of a monoblock pair. The existing gauge of wire would benefit from being a bit larger. So says a respected, certified audiophile and electronics expert whose wise counsel I have trusted for over 20 years. If he's wrong, a reversal would pose no problem.

Buconero117, I sense that you're not a serious tweaker?

See page 2 of this catalog:(http://www.percyaudio.com/Catalog.pdf), for a variety. You didn't specify a gauge, but one of the Cardas chassis wires would probably yield the presentation you desire(I prefer Kimber). Also- use either WBT Silver Solder(off eBay), or Wonder Solder Signature for your project(page 15 of catalog).