Manafont is one of my fav shop's but i would not rely of there measurements to much as they had the TR-J16 as 149.51mm wide at the head loll.
I really honestly think driven the way these multi led lights are normally your not going to see a difference in light out put the eye can see with the U2,s over the T6's.
The UF looks the same as the TR-J12 and the Keygos and so on to me. The trustfire TR-3T6 and the TR-J12 have proven to be good reliable lights and that can handle long run times with no heat sinking issues, with mode memory and dimming mode for low voltage.
I really like that driver as it has no strobe or s.o.s modes If it will run on 12.6 volt ok, you might find the TR-J12 draws more over 2 cells then that driver listed for 5 x T6 but has flashy and s.o.s modes.