I actually ordered some NIMH at 120 mah. I'll give those a try rather than go the L-ion batteries. AFWIW, I may go the route of making my own. I do have (somewhere on this comp) the diagram for making my own as Gunrunner said. As for Marty's comment, I hear you Marty, however The MTH battery meets the same specs as what I have ordered for 1/4 the price, even less in bulk. All that said, Thanks for all the advice and I'll throw in that, these are all the 8.4 volt for either 5 volt PS2 or PS1 units, so I'll assume I'll upgrade when they fail on their own. If one fails because of a poor battery choice, Oh well, lesson learned. I have yet to blow a 5 volt except a sound issue in one and a smoke circuit in one that's going in a MTA subway unit.
Again, Thanks to all!