It looks like DC is the way to go.
Looking at the options, the ProTEC 106B seems like a good option. Since I don't run my NIMH packs that often, I am looking for something that makes discharging them and them charging up to 50% easy. Most of the time the charger will be used to charge my 2S Lipos.
The Protec Super Pro 40 powersupply looks good, but a little pricey. It would allow me to hook up both my DuraTrax 230 and the ProTek, and still be able to plug in a DC powered pit lamp (important as our local tracks races under the lights on Saturdays).
Also - my Lipos at Thunder Power "Pro Race" 2s that have a Thunder Power balance connector. Would the ProTEC 106B need a seperate adaptor?