Roger brought up a good point; if you go to larger capacity packs, you'll need to buy a charger because the one that came with your radio equipment won't be enough. And if you're going to buy a charger, you should absolutely get a "peak detection" charger.

If you're going to buy a new Peak charger, you might as well invest in one that also "cycles" your packs to keep them performing properly. Finally, if you're going to invest in a Peak Detection Charger/Cycler today, you might as well get one that can also maintain Lithium packs, because they'll be replacing NiMH's within a few years. MUCH lower weight for the same capacity.

Wait awhile before you get the stuff you don't need right now. Your "Wall Wart" charger will keep your existing packs charged, and is all you'll need for a while. (Year or so.) DO spend the $15 for an Expanded Scale Voltmeter. You want one that places a load on the pack while testing it. Tower has them, most hobby shops should.
Dennis-