F-27 f/o starts at 25k per year although they are being replaced by the ATR42/72. Don't know much about the ATR life but I don't think it's different. Caravan starts at 32.5k per year and is the better way to go although you may retire in it since life is good and the pay tops out at 55k. Not bad for almost a part time job.
Check out the website- www.airt.net and look for MAC Homepage
For what it's worth I'm happy here but then again all it takes to make me happy is lots of home time, beer and grilled meat.
As with any place your equipment depends on what they need at the time. If you interview tell them you'll go anywhere and fly anything then once you're hired bid on what you want. I think you have to stay one year in the initial plane but after that you're off and running. Upgrades are slow but the wait isn't bad.
The normal progression was 121 f/o, 208 pic, then 121 pic. If you get the van off the bat then go to 121 f/o you bring your van pay over as an f/o making you a very highly paid f/o. Things may have changed with the ATR.