The wattage is higher on the MaxAmps PS because it's 24V.

You need to watch out for that sort of thing, because only a REAL high output charger will be able to use that input voltage, like the TP 820CD I have.

The Duratrax ICE, for example, can only handle an input voltage of 11-18VDC.

It's a good charger, you could get a separate balancer down the road to keep your lipos healthy. Like this one.

For your purposes right now, I kinda doubt you'll outgrow the ProTek 40A PS, it took me 4 years to outgrow my old 10A PS to warrant the current setup I have with that TP 820CD and ProTek Super 1000.