IPAD and Keyboard midi for live gigs

Hi all,
i 'm a musician and i have an home recording project that i would like to bring it in a live contest.
at home i work with my pc, an m-audio usb external sound card,my keyboard midi and i use Cubase 5 with vst.
Recently i 've buy a new ipad and i would like to use it for replace the Pc.
so now i have :

- an Ipad 3 without jailbreak.
- a midi/usb keyboard (1 midi out).
- an external usb sound card.

Now, what i need and how can i use them?
i see many videos where guys use Camera Connection Kit to connect Keyboard with Ipad.Ok,so i't s the best things?and what CCK works?
5 to 1?Apple version or cheap wersion?
i see also the IRIG MIDI for connect keyboard via MIDI.
what is the better? CCK or IRIG MIDI ? MIDI or USB ? Sound card or not?and what i should use for output in a live contest?
thanks in advance,and sorry for too many questions but i think that these informations are really useful for a new future in live music for Ipad.