I'm not familiar with the Mce2s switch, so I don't know if it makes the light much longer, but I carry my E2E/KL4 in a large Benchmade soft pouch. Perfect fit. Stitched belt loop, velcro closure on the flap. http://www.newgraham.com/bm_acc.htm
There is quite a selection of holsters (very economical but good quality AFAIK) made by the BCB company. The surplus store in town has the whole line. I have one of them for my Lumamax L1 that probably would also fit your situation. Almost all the holsters come in flat as well as round/shaped versions. I have the shaped version.