If you make it down to Austin I'll treat you to some of the best BBQ in Texas..
The best bbq (and Blackberry pie) in Texas is the Salt Lick - technically in Driftwood TX - but I never miss it when I'm in Austin.
More on topic, I've never found truly great bbq in Dallas - and I've been there hundreds of times.
For guns, you shouldn't miss Willoughby McCabe & Co. Last time I was there it was by appointment only, so call Pat and set up a time. You'll hear angels sing as you open the door. Make sure you have some time. I've never purchased a gun there, but it wasn't due to lack of choices.