If it were me I'd just get some wide (P35 or similar) rims and some some 29er small block 8s. They seem to work for most stuff at the right PSI, and I'm always in too much of a hurry to swap tyres on the way out of the door.
A more XC style width rim will take 2.2" 29er or a 32mm commuter tyre. If you're more inclined to swap tyres around.
If it were me I'd just get some wide (P35 or similar) rims and some some 29er small block 8s. They seem to work for most stuff at the right PSI, and I'm always in too much of a hurry to swap tyres on the way out of the door.
A more XC style width rim will take 2.2" 29er or a 32mm commuter tyre. If you're more inclined to swap tyres around.
New wheels means cassettes, brake discs etc etc.