Right now the way Alt.Binz deals with .par2's that have .001 .002 .003 and so on, is to just show the one file in the par2 section, so instead of showing:
Blah.rar.001
Blah.rar.002
Blah.rar.003
etc
It shows just
Blah.rar
Then when all the parts are finished downloading it doesn't do anything with them. With QuickPar you can press rejoin and it will join together the files. I think Alt.Binz could join together the files and unrar.