Driver advice needed - Red XP-E2 Triple/Quad single 18650

Hi, I'm looking to build a triple or quad Xp-E2, haven't quite decided yet, to put in a P60 host (so 17mm diameter preferred, but not absolutely necessary if I have to change hosts), with dtp pcb and some narrow spot Carclo optics. The Vf on the red xp-e2's is considerably lower than the other colors/tints, so if I want to run 3 red xp-e2's in parallel, can anyone recommend a decent driver for this application? I'm not very experienced by any means, but after searching the forum and internet for a while, no obvious driver choices come to mind. Would things be a lot easier if I changed the theoretical setup a little? For example, running the LEDs in series with more than one 18650, etc..
My only idea so far would be modding an LD-4b buck driver for increased current, from stock ~2.4a to somewhere around 4.5a if this is possible. That way the buck driver would dissipate some of the difference in voltage between battery and emitter, and the light would be getting around 1.5a per emitter for really good output (by red led standards).
Does anyone know of a driver thats readily available or easily modded that would work for this lower vf? Thanks!

For single li-ion application, i would definitely go with the H17F driver.
It is probably one of the best driver out there for single cell lights, with lots of programmable options & features.
They are 17mm in size & you can get them at Mtn Electronics

There are a number of ways to drive red LEDs. You can technically use a linear driver but it will have to dump a lot of heat and while with thermal potting it may take it, it's far from ideal. The two ways I've done it before and it worked great were using a buck driver which does have some space and current issues or using a linear driver and a LiFePO4 battery which has much less space issues but you sacrifice battery capacity. You probably could resistor mod the LD-4b up to 4.5A and it might take it. the coil is pretty big I would just be worried about the flyback diode and maybe the FET. Potting the whole thing would help with heat issues. I don't *think* you would saturate that inductor with that much current boost but I'm not sure.