Weber Kettle or build UDS

If you want both, get the kettle. 22", It will take some effort to smoke with it, but it is doable. Long smokes, like pulled pork will take a lot of work, ribs or anything below 5-6hrs are fairly easy with some effort watching temps. and reloading the charcoal to maintain temps.

UDS is great for long smokes, it's pretty much set it & forget it.  I've never tried grilling with mine, but it may be doable if you leave the lid off and let the charcoal get really hot. Typically with a UDS the grates are too far away from the coals to get a really high heat.

Best case... get both.

First of all .. Propane grills are great and fast heat, but nothing until you cook over charcoals
The weber 22 silver is like $89.00! Unbelievable... The gold with the fancy clean out bucket and the hinged grates is another $50. Well worth it!!! You can smoke almost anything on it and then go ahead an que the best steak with on it.. Super versatile.
Everyone should have at least one in their collection.. I have 2... I bought a 18 at a garage sale for $5.00. Couldn't resist.
Ps go to you tube and look up bar b cue put boys.. They do 90 percent of their smokes on a weber!!!!

If you make adjustable grates and or an adjustable height rack for the charcoal basket you can get the UDS up to super high temps. The rack system in my UDS allows me to raise or lower the racks in 1" increments from the top to the drum to the top of the charcoal basket. I have had my UDS above (450, highest my therm goes) many times.

I don't use it much though as I rarely do large cooks. If I do I typically use my WSM 18.5. Which if you take the body off you can put the grill grate on the base right at charcoal level.

Forgot to mention I believe that the Big Poppa UDS kit has an adjustable charcoal basket system that allows you to lower or raise the basket.