E-Drums require a slightly different technique. You shouldn't play an ekit as hard as you would a real kit, because the ekit doesn't have the dynamic range to truly response to that kind of playing.
But if you're starting out, it's probably not too relevant to you. Just get a kit that is constructed fairly well and has some expansion options. I recommend the Yamaha kits at the moment. They're beating the Roland ones for me. Steer clear of RET drums... they don't respond at all to dynamics, and produce the guffest midi data I've ever seen.
When you get one do the following:
Go into the velocity/gain controls. Hit the pads really hard. Make sure your output velocity is peaking at about 122 - not 127. This gives you a little bit of headroom, and any software anti-machine gun modes will perform better on harder hists.