Will 18v NiCd drill batteries (cheapest option I think) be able to supply power to 4 12v drills and possibly another drill for a lifter weapon? If not, will NiMH?

I have looked at the thought of wiring two 8.4v, or maybe 9.6v NiMH packs in series but I don't know how I'd charge them? The problem it would seem for any kind of battery, is that the battery itself isn't very expensive, it's the charger for the battery that leaves a serious dent in the wallet.

Any ideas for getting 18v batteries (in the region of 2-3Ah), and a charger, for around 20-30 quid? Drills still seem to stand out to me but they're often NiCd and I don't know if they can supply enough amps for what I'd be asking for.