Move your pointer up to the top of the page and click CLUB STORE>WINCHES. That's where I got my Viper v1 4500lb winch. Works good so far. There's now a v2 version that looks pretty sweet.
Also, KFI, SuperATV, Mile marker, all seem to get good reviews.
3500 is probably fine, but I went 4500 for a little extra power for cycling a plow up and down.