Okay!
You'll probably be fine with a WiFi only version if you have plenty of WiFi hotspots in your area.
If you want to store and watch a lot of movies on your iPad, I don't think 16 GB iPad will hack it.
The actual storage size of the 16 GB iPad is only 13.5 GBs of free data space.
If you don't include the space additonal apps take up on an iPad, most movies in HD are around 3-4 GBs in size.
This will leave room for only 3-4 movies.
My opinion, but I think you would be better off and better served with either a 32 GBs (28.5 GBs actual storage size) OR, if you so choose, the 64 GB (57.5 GBs actual storage size) iPad model.
Both leave room for additonal movies storage plus still have room for say music, photos and additonal apps.