µTorrent is the most reliable and easy to use Download Client you can find in the internet for free. It is a little over 1 MB and it installs ultra-fast with a light footprint on your computer, and runs super-efficiently.
Wineskin is a tool used to make ports of Windows software to Mac OS X. The ports are in the form of normal Mac application bundle wrappers. It works like a wrapper around the Windows software, and you can share just the wrappers if you choose.
Best of all, its free!