[Kevin Sevcik]

If you're expecting a true 0-5V swing on your PWM/DAC outputs, you'd be wise to use an op-amp to drive your gauges anyways. The sourcing/sinking current on the ATmega outputs drops fairly rapidly the closer you get to 0V or 5V. If you're running onto an RC filter to get your nice analog voltage out, those nonlinear currents are going to play heck with your linearity. Plus you can use whatever filtering you want at that point.

Also, to Don:

In Houston, Electronic Parts Outlet (EPO) is a decent surplus store, and Ace Electronics is a decent part shop. So there's definitely some good places left here and there.