Personally - I'd figure out how far you guys are going to take this. You say in the past you have ended games after 3-4 months. Depending on how often you play, if the same thing happens you may never get past 8th level or so. I'd plan accordingly if that's the case.
I'd play a Wizard - Gnome Illusionist as a matter of fact. (Partly because an aborted campaign forced me to stop playing one recently.) If you are playing with limited spells and all that low level restriction, you might as well be as creative as possible with your spells.
Druid seems to be a popular answer. Honestly, I've never had a player have a bad experience with playing a druid - I've even had a serious suggestion that our next campaign specifically an all Druid game. It's an "overpowered" class some would say, but even if everything were balanced out numerically, I still thing the flavor and the variety of things it can do make it a fun class to play. But things just start getting REALLY interesting about the time your campaign may end...
Ive found low level Clerics often bore people, but its another solid choice IMO.
An artificer for a low-level start campaign may be ideal because your group will want magic items as soon as they can get them and if you can't mitigate the standard XP loss somehow, well, let's just say those first few items are gonna hurt.
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Just to chime in my opinion of low level games, I also prefer starting games at low level. (Yes, low level, low power - I know some people are probably horrified at this point). I agree with previous posters regarding the "Why". It makes people invest more in their characters and gives a real sense of accomplishment.
Yes, I do see more multiclassing, no I don't see such a massive disconnect between spellcasters / melee but my group savors those low levels and by the time they reach a sufficiently high enough level for it to start to matter, they have become more of a "group" with a real place in and sense of the campaign world so the "rules balance" is almost a secondary consideration.
I also use an alternate "Death's Door" mechanic. I let PCs fall to negative Con before you die and allow consciousness (with progressive penalties) up to -1/2 Con. Of course this can be a good or bad thing, though I find with the Concentration skill, and the low HP start, spellcaster's often opt for Con as a top priotity stat.) At the very least it helps survivability of low HD classes and gives them a last ditch opportunity to stay on their feet and do something (which usually amounts to crawling toward a healer, or drinking a potion, etc.) But I do think using some sort of HP boosting rule or alternate Death's Door rule is key to low level gaming. Unless your group just likes to make new characters and takes PC death in stride.
