As you can see there are lots of options.
Much depends on how good of ski wake you are looking for. Of course you can Ski behind any boat. If you want to Simi seriously Slalom Ski Crossing the wake aggressively you are going to want either a DD or a Crossover V drive like the
CC 211 or the new Malibu V drive Crossover boat.
I just purchased the new Centurion 216 crossover boat
http://www.wakeworld.com/MB/Discus/messages/3183/407802.html?1169914123 that I am itching to get on the water.
Of course a demo ride is the best way to see if you will be satisfied with the ski wake