UDS is definitely the way to go. Its not as expensive as a WSM, you know exactly how it works because you built it. Its easy to mod if you think it needs to be tweaked, but honestly you don't need to mess with it unless you are a perpetual tinkerer (like I am) and that won't necessarily work in your favor (see below).
Tips from my own personal experience:
- If you use a remote thermometer like a Maverick et732, then don't bother with grommet type mods. Just cut a small shallow notch in the lip of the drum, so that the probe wire does not get crimped by the lid against the rim.
-Forget foiling. Wastes time and foil.
-Make sure you have 2 racks to cook on, possibly a third rack for a clay saucer or other heat deflector. Make sure the top rack leaves enough head room for turkeys, etc.
- I added 1 pipe valve on a riser (fat man mod) so I wouldn't have to bend down all the time to adjust temp. Then I added risers to the other 3 intakes so I wouldn't have to bend down at all (fat AND lazy mod). That's when my drum stopped being able to make it above 270°F. Lesson learned: don't mess with the UDS design too much. (I added a 5th intake 1.25" without a riser and can easily do higher temp cooks now).
And of course, the big UDS thread is an awesome resource!