K10 vs K20 vs K30: Which For Me?

[semperfidoordie]

I am writing as I am wanting to pick up a 4x4 truck for daily driving and offroading on the weekends. Cab configuration isn't a concern to me I like all cab types however don't want a dually. I plan on running a pretty big set of Swampers on it and was curious what you all thought. I wasn't sure how the D44 holds up to big tires and am looking to the experts. I think a K30 SRW is right for me but unsure...I drive 9 miles one way to work each day, currently am stationed in 29 Palms, CA (See: Desert) so it needs AC, will be moving back to Alaska (see polar opposite of here) in a year and a half. No major roadtrips will be taken in the truck the longest it will go is probably an hour and a half away on highways with speed limits of 55-65. What I really would want is a regular cab shortbed with a big block and axles capable of running some 38-42" tires on but need a DD that's ready to roll and I can build slowly.