I believe from my reading that I can re-use my AS Number with IPv6 without effecting my IPv4 routing but I obviously want to make sure.
Yes, won't matter at all. However, keep in mind the whole bgp loop-prevention thingy. If you're running two islands of ASXXX, they will not be able to see each others routes because it looks like an advertising loop. (This probably won't matter to you since one island is v4 and one is v6) (You can fix this with a default route or other statics).