i remember reading that the XTE gives a weird hotspot because of its unusual die.
but xpg 2 or xpe 2 should fit.
3 D cells should provide enough amp to XPL.
consider XML2 as well. do u care about tint?
many ppl like warm white.
i usually order emitters from FT coz i trust them. beware that there are some fake Cree on the market right now. see here