I started out with a vertical propane smoker similar to that one. It was a decent smoker to get my feet wet with, but I found once I got more involved in smoking I couldn't wait to get a charcoal cooker. Not to mention those propane types aren't as set and forget as one would hope. You still have to fill them with wood chips or chunks periodically. My advice would be to save your time and money and just get the WSM from the jump. If price is an object then build a UDS. I have an XL egg but I'm building a UDS anyway. A man can never have too many cookers and they just look like a lot of fun.
Whatever you decide, the most important thing is to hang out around here, it would take an enormous collection of books to get the same amount of knowledge you can find here for free. If you have a question, ask away, the folks here are more than happy to oblige.
"I can get a good look at a T-bone by sticking my head up a bull's a$$, but I'd rather take a butcher's word for it". - Tommy Callahan III
XL Big Green Egg, 22.5 Weber OTS, WSJ Gold/Mini WSM, 18" & 22" WSM, UDS "No.8"
Flyers Orange Thermapen
Napkin Killers BBQ