Another one is ssX or soulseex. It always worked well for me. I can't figure out how to install Nicotine, but I guess that's the slightly more advanced soulseek client for Mac,
If you must run a Windows program, first try "Wine" or if you need it the comercial versin of Wine callled "crossover". Wine can't rn all Windows programs. So it that fails use VMware or the like to run Windows onthe Mac and then your software. It is very transparent and works well but does need lots of RAM