If you haven't already ordered the MC-Es, I'd get them in 5A tint from the following group buy:
http://www.candlepowerforums.com/vb/showthread.php?t=211450
This tint is pretty amazing -- roughly in between cool white LEDs and incans. You'll sacrifice a few (hundred) lumens, but IMO the result is worth it.
This thread shows a comparison of the tints.
5 MC-Es sounds quite impressive, what are you planning to use for a battery pack?
Right now I'm running my
Triple MC-E 2C Mag with
these $7 LiIons from DX. 3 warm white MC-Es in direct drive (6 parallel strings of two dice each), with every possible source of resistance in the light removed. At roughly 5 amps load through most of the runtime, driving 3 MC-Es is the most two of these cells can safely deliver.
For 5 MC-Es you might be able to get away with two of the LiIon D-Cells from Kaidomain in a 2D direct drive, or 4 LiIon C-cells with 4-series wiring of the LED dice.
Also, one suggestion if you're planning to go direct drive is when you wire strings of LEDs in series, each LED die in the string should be from a DIFFERENT MC-E package, instead of connecting all four dice on each individual MC-E in series with each other. This will make a thermal runaway situation less likely when direct driving LEDs in parallel.
When one parallel LED (or entire parallel string of LEDs) heats up more than its neighbors, its Vf will drop, causing it to draw more current, and heat up further, leading to a particular runaway situation at worst and uneven brightness at best. This could happen if you have say all four of the dice on each MC-E connected in series to each other, then all 5 of your MC-Es wired in paralel.
If instead you wire your LED strings so that they are composed of one die each from four DIFFERENT MC-Es, there won't be any problems if one of the MC-E packages heats up unevenly. Instead of shifting the Vf of one LED string dramatically and creating a possible runaway situation, it will shift the Vf of 4/5ths of your strings only very slightly.
