Re: new boat for me
Consider buying a well maintained used 2stroke outboard. The Catalina 22 will be pushed well with anything from 2-6hp... 3hp being ideal (with self contained tank). I use a 2.2hp on my 25 footer, and it pushes the boat to 5knots... its too small really, but I have no regrets... cost me $300 from a local boat house, and it was a bargain, runs like a top!
Otherwise, the Cat 22 is a great boat, and has a really strong OD class. There are tons and tons of upgrades available for the boat, and lots of aftermarket parts for it. Used sails are also easy to find, ebay and craigslist are your friends.
Electric outboards are fine, getting the crazy big ones are pricey but pretty slick. If you aren't really going to to use the outboard at all (except in and out of the slip), you can get a big transom mounted trolling motor, but like others said, it won't run real long or be super powerful (just very basic maneuvering - which wind can overcome pretty easily). You'd have to get a massive solar charger, or plug in to keep the battery topped off.
Still think the 2 stroke used outboards are the least troublesome, as long as you get one that is well maintained (and you continue that maintenance). If you can't stomach the "damage to the environment" of that, then look for 4 stroke or electric, or also the new LP outboards (all very expensive options).
As a last statement, and as much as I LOVE To sail, having a good kicker is invaluable for getting you to a destination in a timely manner when winds give up on you. Also they are invaluable for when you've "had enough" of fighting weather (remember rain can get old too). While I'd prefer to sail into my slip every time, time constraints, weather, and lack of sleep sometimes push me to fire up the iron genny, so having a reliable no maintenance kicker is a must for me (OK I am not a sailing purist, I admit it).
"Rum Line" an S2 7.9 - cheap, fast, trailerable, and paid for.