Hi..I have the exact same Alesis IO2 and it works very well..just make sure to turn down the Gain down to zero to get the full effect of the AMplitube fx or it will distort the sounds...make sure you also turn the one dial all the way over to USB so as to get the full volume from the guitar.
Reaper is the recording software I use and its awesome considering its free :)
I have recently bought GUITAR RIG 5 and the Rig KONTROL 3 pedal. Very impressed ! I would say that Amplitube is slightly more organic sounding than the Guitar Rig but I use both in different tunes.
Good Luck and ENJOY :)