Papa'ele'ele is just a personal favorite. I find it to effect the head more than Mo'i, which, for me, is more of a somatic/body-high. Moi'i is great, though, but I'd consult Mr. Yee or his literature bank to find the right cultivar for you.
The Tuday (Isa) is indeed a mystic pepper, and I'd caution against its use by newbies.