Welcome to CPF Damelas!
Double A's made a great suggestion. The E2E is small and bright and light enough to always be on your belt. However, a rechargeable is going to be more practical and economical if you often patrol dark parking lots, or work night shift. If you implement this two light setup, I'd even recommend the Stinger HP, which is brighter than the regular (SL says up to 15,000 cp for Stinger, 40,000 for Stinger HP). If you aren't going to always carry it, the extra three quarters of an inch and 2 ounces won't bother you at all.
However, you may not always be near your desk or vehicle to get the Stinger and put it away. THen you are left with one light, always carried. The E2E is still a great light (bright, small form factor, durable HA finish), but if you use if often, the pile of dead batteries will mount quickly.
Another suggestion is to get a Pila, like the GL2, which can either utilize rechargeables or lithium 123s. Then you could use it as a rechargeable on a daily basis and carry two 123s on your belt as backup power source. The Pilas even have an LED in the tailcap! In addition, there is a 3x123 Pila, too.
You started the thread with the SF 6P and PM6, both are nice lights. That said, I think the SF G2Z might be better for daily use than the 6P, because the G2Z has a nitrolon polymer finish and Pyrex lens (so you can use a p61 with impunity). If cost is a big factor, the PM6 is a contender, but I'm not taken with the aluminum finish, seems like it won't take much abuse. And if the casino will pay for batteries, you may not be need a rechargeable, tho having a gadzillion dead lithiums ain't optimal, either.
Welcome again, and let us know what you choose!
daloosh