you would need to get a different mother board if you want to go with the i5, the 1055T is an outstanding processor, and the only difference i can see between the 1055T and the 1090T (other than the $100 difference ) is that the 1090T black edition has an unlocked multiplier, which only means you have another tool to use when overclocking. if overclocking to the absolute max isnt really your thing, then go with the 1055T.
Also, if you want to go with the i5, im pretty sure, if its anything like the i7 processors, you are going to need tripple channel ram, which is more expensive then the ram you are going to need with the 1055.