Integrated amp with digital to analog converter?

You will need one of the few docks which can extract the digital signal from the iPod anyway. To my knowledge the only such docks are made by Wadia, Onkyo and MSB (at varying price points). There is no other way to get the digital signal from the iPod to a DAC so you will need to factor one of these docks into your budget.

Tact s2150 used would be in your price range

Bel Canto S300iu, though the DAC is USB.

What about the new Onkyo A-5VL integrated amp?