MAH == Milli-Amp-Hour, a measure of the stored power in the battery.
The actual voltage rating of most NiMH and NiCd bats is 1.25. That's essentially a law of physics. It doesn't matter the size of the cell, it's still 1.25 volts. Most packs are rated as 1.2 volts per cell, so that an 8 cell pack would be 9.6 volts. They loose that 0.05 real quick, so it's generally not considered. Freshly charged, they'll read as much as 1.4 volts+, but as soon as a load is applied, they drop to 1.2.
Got Panasonic AA's at Costco; 1600 mah; 6 for $12.95. AA's was all they had in NiMH's.
Got 4500 mah D's at RS: 2 for $14.95. Hate to say anything nice about the Shack, but it was the best price/power I found.
Probably gonna get a couple Plainviews for my 9 volt TAH.
Hope some of this helps.
Edit; Welcome to Head-Fi, sorry about your wallet.