I don't have all that much experience. I know the go-to on the BBQ forums would include the Green Egg, Weber Smokey Mountain, and even a regular old Weber kettle grill.
I will say, I have a really cheap
Brinkmann upright charcoal smoker and it rocks. I think I paid $89 for it available at all the usual places, Lowes, Home Depot,
Walmart. It certainly isn't the best smoker out there, but I love it. The cheap ones generally have problems with getting the temperature right and holding the temperature. All I did was replace the stock solid charcoal pan with a pan with holes in it for airflow. I can't achieve low temperature, I can't achieve higher temperature, but when it comes to 90% of smoking, you want and my Brinkmann seems to hold 225° perfect and forever. I start a chimney half full of lump charcoal and dump it on a bed of unlit coals and 3 chunks of smoke wood. About every 45 minutes I have to put in a new chunk of smoke wood and every hour or so I check the pan of water, refill, and toss a handful of charcoal in it.
I am usually swimming in the pool while the smoker is chugging along in the yard. Like I said, it stays rock steady at 225° all day long. My 2nd rack of ribs were the best ribs I had ever eaten in my life.
I tried a whole chicken but for crisping up the skin you want 275°. I couldn't achieve that and cooked a little longer at 225 and finished it off on the grill for crisping up the skin. Took 6 hours, but it was fantastic chicken.
There is plenty of info on the web on how to make the Brinkmann vertical smoker work fantastic. The Brinkmann smokers are known in the BBQ world as CAB's (Cheap *** Brinkmann.) They are cheap, it takes just a little bit to modify them (new basket, sealing the doors) but they do work very well for very little money.
Oh, and like I said, mine is charcoal and I use lump charcoal (Royal Oak at Walmart is fantastic, did you know there are websites entirely dedicated to assessing the quality of all the available charcoal?) I would never bother with an electric or gas smoker. Smoking is as much about the process of cooking the meats as the yummy end results itself. A lot would be lost without the charcoal, and lump charcoal is the way to go without all the chemicals that is in the standard (read Kingsford) charcoal briquettes.
After the smoker gift, to get started, make sure he googles the 321 method for cooking ribs. The absolute best way to cook ribs.