Aluminum wire has its place in our daily lives but definitely not in automotive applications.
Personally I like commercial grade multi-strand electrical wire like they use in conduit because the insulation is much better than what I can buy at the auto parts stores. If you know any electricians or HVAC people, maybe they will hook you up with some left overs.
I didn't know we could use that kind of wire. I could have sworn I read somewhere not to use that. Not sure why; it's stranded copper with great insulation like you said. I've got some laying around. good to know I can use it. thanks