Hard to beat the Dat2zip Luxeon drop-ins for the Minimag. I personally can't afford the current Arc LS prices, and the minimag modifications are a much more affordable alternative (see Everything you ever wanted to know: BADBOY, MADMAX Update. I think this is the longest thread on the whole entire CPF board). If you get the glass lens and a Kroll tailswitch, they'll be about the same size as your Surefire KL1 setup. You can get Wayne's stuff here, go to the full sandwich mod kits and accessories pages. I personally prefer these over the Opalec, but that's personal preference. I have been at CPF for only a little while, and I have already spent way too much money, so watch your wallet! Welcome to CPF!