I worked in HVAC service, then design/build for about 20 years, Bob.
Jarrod is right on the ball. I just wanted to chirp my reluctance in adding a humidifier to the furnace. They all suck. They calcify, fail, leak, run water all over everything, and are generally junk right out of the box. They don't work worth a damn, and require constant maintenance.
I'd suggest to you a nice big console humidifier. We run one upstairs and downstairs all winter and they work great. You could easily get away with just one for the size of your house, I'd think. You just fill the jugs when they're empty and replace the wicks halfway through the season.
You can get the humidifier, wicks, and destinkerizer juice at Lowe's. Easy peazy, under 200 bucks and they last forever, so far as I can tell.
On the furnace, there's lots of brands, and at a time they were most, if not all, made by York, which is a really nice furnace. That's what I'd go after, personally, but there's no big difference across brands nowadays. Just try to find one that's well made. Rheem is, as Jarrod suggested.
The only brand I'd steer you away from is Trane. They use proprietary parts in their furnaces so that only Trane guys can get parts to fix them, and they charge you out the wazoo when they do. You, as the owner of the furnace, could not even buy parts for it at one time. That may have changed, but I've not heard anything about it. Maybe Jarrod can add more to that.
One more thing, I'd steer you away from anything that uses hot surface ignition. The ignitors fail constantly. They heat up red time and time again to light the furnace, then simply crack. Then you're in the cold. It's been a long time since I've seen them used in a furnace, so I'm guessing people in the industry have forgotten what a failure they were and started using "new, improved" ones by now. That's how the industry rolls.
