Reply to iPad mixing

Hi all, needing some help. I'm gunna buy an ipad 2 to do mixing on.. just wondering what spec ipad i should get 16/32/64gb etc. Can you use TPRO2 on these? I was looking at the i rig system looks hot? Or can you use a Tablet?

Sorry if this has already been asked.

Any advice/help very much appreciated, thx Rastey