You want a white light for blood trailing. Other issues are portability, run time and throw.
For sure my favorite is the Surefire G2 modded with a p90 or equivalent with 2 unprotected 3.6V. Lot of folks don't like running unprotected cells in series though. I think AWs protected cells will fire it up, although I haven't tried.
I think though the new G2 LED run with an AW P18650, might be a good one as well, I'm waiting for a Cree Drop in to check and see what that will be like.
Another nice one is the Nuwaii Q3(or whatever model that is now) on one unprotected 3.6V. Overdriven white light and great flood for trailing. Unbelievably compact, extra long bulb life, tough as nails, not a lot of throw though.
If there is poor blood I use a modded 2C, some kind of ROP iteration with a lower drawing bulb for a longer run time and a smooth reflector for greater throw.
Last year a buddy of mine shot one high, no blood. I had both of my unmodded G2's side by side, in order to scan the field, it was barely enough light, to find that buck.
I'd suggest 2 lights one that is compact with good flood with a bright white light, for blood trailing, that you keep in your pack. Either the Nuwaii Q3 or maybe the G2 LED. Something like that.
And then something with more throw that you keep in the truck. Like maybe a Magcharger if you're not into mods.