Best Way to get a 6 cell Battery?

[kuma]

I'm about to buy a T42 the 2373GVU, but it only comes with a 9 cell battery. What is the best way to use the 9 cell to get myself a 6 cell? I also want to get the slim bay 4 cell battery.
What is the best way to go about this?
Sell the Brand new never used 9 cell on ebay? And buy the 6cell and 4 cell on eBay? Will these be new and hold a charge as well?
Or should I traded the 9 for 6 here on this website?

Thanks.

[ctbenski]

where are you located? Where to get a battery deal dependes on this circumstance.
BTW, I might be interested in your 9-cell