You may want to explore the iPod docks from receiver/amp manufacturers such as NAD, Marantz, Denon, etc. I have owned or heard all three of these manufacturers docks and was impressed with the quality of sound from them. I recently heard the peachtree iDAC. For the price difference ($1,000 vs $150), I would suggest putting the cost difference in to other components of your system such as the amp/receiver or speakers.
You could always upgrade the iPod dock at a later date. If you are interested in hi-res audio, 24/96 or higher, as far as I know, iPods cannot transmit at the higher bit rates (someone please correct me if I am wrong). Therefore, you may want to shift funds to utilizing computer audio for hi resolution playback.
Part of the fun in purchasing a system is auditioning gear.
Good luck.