I'd recommend looking at a charger that does Lipos. While they may not be ideal for tanks right now (we don't care about weight as much as the racers or aviators), I suspect in a few years the price of Lipos will be even lower and the higher capacity will be worth it. Plus, RC is a like a disease, before you know it, you'll be infected in multiple ways!!!!
(tanks, planes, helis, micro indoor, truck are my symptoms).
Anyways, if you're going to spend a few bucks on a charger, the lipo compatible chargers have dropped to the point where it's worth getting a good multi-charger. I have a Multiplex LN5014 as my low end charger and it does a great job on my plane, heli, and tank packs. Was about $80 when I got it, and it's sold under a bunch of names (Swallow Advance). Triton Jr. is another good "bang for the buck" charger.
PS. On a side note, the MRC 969 may be a good standard charger, but even though it was once advertised as Lipo compatible, it's not. I hear MRC will upgrade it to a 977, possible for a small fee, but the stock 969 is dangerous with lipos. I think it's EOL anyway.