AEO

105 hubs are pretty durable, it's all in the rim and wheel builder for durability of the wheels.

The best part about shimano is that you can use 9sp road shifters (new Tiagra, old 105/ultegra) with an XT dérailleur, crankset and XT 9sp cassette.

I for instance have a 34/50 tiagra compact double crankset and 105 FD with 11-34 deore cassette and RD that is possible with 9sp 105 brake/shifters. They'll mix and match no problem since the cable pull is the same.

Naturally you can do the opposite with XT cranks and 105 cassette, but all you have to worry about is keeping the number of cogs on the cassette the same as the shifters. 10sp cassette with 10sp shifters, 9sp cassette with 9sp shifters. Dérailleurs and crankset don't particularly care about 9/10sp, they'll work with both.

9sp is slightly more durable than 10sp since the chain and gears are slightly thicker. Also cheaper to get replacement drive train parts for. SRAM 9sp chain is particularly amazing for it's price.

p.s. I totally forgot about covering the brakes. If you get road style brake levers you need to use cantilever style brakes. If you get MTB style brake levers, you need to get V-brakes. What it comes down to is the amount of cable pull is different for both and if you mix those, all you are going to get is trouble.