ThinkPad X41 battery replacement - recommended vendors?

[rampancy]

So I'm planning on fixing up an old ThinkPad X41 that I've had in my collection for the longest time (all it needs is a new internal disk drive, and CMOS battery), and I'd like to replace the main battery, which is dead. Are there any suggestions for places to buy them? Google searches turn up a whole bunch of different replacement battery vendors I haven't heard of, and there's hardly anything available on eBay.