I bought an industrial
gun that uses 1/2" dia. (0.468" actually) sticks with variable temp. It's sold under a bunch of different names / brands.
There is a
HUGE variety of glue compounds available in that stick size and the variable temp on the gun lets you run all of the them. I use a lot of the acrylic sticks as they both bond really well and have enough flex that they don't crack later. They take a relatively higher temp.
Most of the big-boy guns also have tips that can be swapped out with different geometries. I haven't needed any of the specialty tips but maybe you will? For instance carpet installers use a fan tip to dispense a wide stripe...
One aspect that I haven't needed but that may matter for you is how much volume you can put through the gun in a given time. Most of the industrial / pro guns give you a spec. for this.