I see your dilema, Ive through the same issues with the ipod. There is no easy way of getting round this prob. The standard head unit, while good quality, is basic and rather old fashioned and featureless by todays standards. In the end I bought a new head unit for £160.00 which plays cd,dvd,radio and most important for me, SD card. Ive put all my music (approx 200 tracks for now) onto an 8GB SC card. I'll never be able to fill the card, and I can navigate the menus through album to track. I also use the remote control to flick through music when Im detailing the car and have no need to carry lots of CD's anymore. You dont have to spend lots on a head unit unless you want a well known brand, and then you are paying for the name.
Cheers Steve