You said growing family, so I'm assuming you'll jump to a Super Crew as well.
Pricing will be a factor (unless that's not an issue for you). Tremor will probably not be discounted as much, and it's more expensive to start with. If I price one out, it's at least $55k with essentially no options other than the Tremor package.
F150 XLT with FX4 would be $8k less MSRP, but most likely around $40k purchase price. If buying used, most likely in the mid $30k's.
It sounds like the 1/2 ton is working for you. I'd stick with an F150. XL, rear locker, STX package, 36 gal tank. $33k. Done.