I went through this exercise last year - I wanted iPOD on-screen menu on my TV and linked TV's and the ability to control through BEO4 from any room.
The answer is a bit of a bodge but works flawlessly and appears totally integrate.
Onkyo make a dock that gives on-screen display, I bought that and a Lintronic box to convert the onkyo to beo4 codes and an automatic video selector which allowed me to plug in both the doc and a Panasonic DVD player into the DVD socket on my TV. I adapted a scart lead to give the data commands to the Lintronic box and to connect to the automatic video selector. DVD and IPOD plug into the video selector. Lintronic was programmed for teh DVD and Onkyo box. Result is that you can press DVD then Green and control the iPOD from any room and see the menu on any of the link TV's and press DVD then Red and control the iPOD - all of it is hidden away. A plus point is that anyone can bring their own iPOD round and that can be used instead. It also freed up the AUX socket on my BS3000 for a turntable and tape deck. Total Cost was around £200 which is really cheap considering the functionality and ease of use and the fact that it is a link solution. Another plus point is that the doc can be changed in the future as more sophisticated and better on screen displays become available for only the price of the docing station - the lintronic box and video selector stay in place and only the lintronic needs re-programming.
Beovision Avant 32 RF, DVD1, Beovision 1, MX4002, Beound 3000, Beolab Penta MKII, Beovox Penta, Beolit 707, Beolink Passive, Beovox C30, Beocom 4, Beogram TX, 4 x Beo4, Form 1 & 2, Beocenter 7700, Beovox S65,