F-5XB or F-3X for Nikon D3000 + 18-55mm + SB400 + 1 additional lens

I'm looking for the ideal "travel light, single camera" casual day bag for a D3000 + 18-55mm + SB400 speedlight + 1 extra lens (nothing massive; maybe a prime, maybe a 55-200mm). An extra pocket or two for filters, extra memory, etc. wouldn't hurt, but isn't crucial.

According to the website, the F-5XB might be perfect, or it might be just a smidge too small (its height is 6 inches, and the D3000 stored lens-down measures a smidge over 6 inches). Anybody out there with the D3000 (or D60, or D40x, or D40) with the kit lens who can tell whether it fits just right or a little too tightly for comfort? Or should I just go with the next size up (which looks like the F-3X)?

I'd just as soon walk into a store and check myself, but they don't sell Domke's in my neck of the woods.

Many thanks,
A

Might be a bit tricky with the F-5XB. It'll fit for sure in a Domke F-10.

I'd say F-3X, F-5XB might be a little small if you want to carry everything you said...