It doesn't really matter, actually. Even if you got the 3.2.1 model, you can't backup its SHSH blob, and when it fails to start, the only option is to restore as 3.2.2 since Apple has stopped signing 3.2.1 for a while now.
3.2.2 is the current iPad release, it will be sign until a new firmware is available.
@OP, you cannot tell what FW is on the box before opening it. But if you got it recently, it will have 3.2.2. Week the oldest the week the better chance but week 34 is going to be 3.2.2 for sure. the ipad have been selling like hotcakes, almost not retailer actually are stocking for more than a couple of days, so no old firmware is out there.