Ipod or MP3 for hold music; mono adapter?

We are in need of a new music server for our on hold music here at the office. We have been using a 5 cd changer on constant shuffle & it has never really worked to our satisfaction. I am Ipod Mp3 illiterate so please bear with me.
First can this be done? It needs to run 24/7 and I don't really care about quantity of songs.
Second it need to be able to be plugged in and charged of course & able to stay on play in case of even short power putages.
Third (and this may be a hangup) it needs to be in mono. If there isn't a player that will play in mono, can we plug in a mono headphone jack or use a stereo jack and run the L&R legs together?
Any insight would be awsome.
Thanks for your time, John
The other option is Dishnetwork, directv or cable. You simply leave it on a music station. You can run a Y adaptor in reverse to combine the signal.
Thanks for the reply, but we are trying to keep it simple without some sort of subscription, etc. Can 2 channel wires be combined for mono on any type of a device? I seem to remember that mono ear phones have a longer section on the plug sans the R&L insulator. Will this work without frying a player to make a mono output?
The fewer moving parts the better, although iPods aren't meant to run 24/7 you can always go cheap (like a Shuffle) and replace them when they burn out. I think Apple will provide some kind of a credit towards a new unit if you bring the old one in to recycle. If you already have some kind of cable or satellite service in the building you might also consider using a dedicated receiver to play music from one of the music channels. Given that dishes are subject to weather, etc... it would not be a great idea to put one up just for hold music.

Using a Y cable to sum the two sides should work fine. Provided you don't have any Beatles on your playlist the average Joe/Jane on hold probably wouldn't even notice if you just used one side. If your source doesn't provide enough juice or if there are impedance matching issues, you can try a music on hold amplifier in line like the RDL TX1W.

If you're a large business, unless you're already paying licensing for the music (and this gets complicated quickly with MP3s) you may want to consider some kind of a service (Muzak, PlayNetwork, DMX, etc...). These services pay the licensing fees for you so you're covered if ASCAP/BMI come knocking. Such instances are rare, but it does happen.
Marqueemoon- What would keep the Ipod or Shuffle charged? Someone last night mentioned an MP3 player. I guess I'll go shopping and see what type of simple system I can assemble. Our PH system is semi-old 10-12 years old but a great system. We just need a mono device that plays maybe 5-10 CD's worth of music, repeats forever and stays charged.
Sorry. I guess I'm not up on iPods. Looks like you might have to use a Nano to use a dock charger. I could be wrong though.
Why not buy a little receiver at best buy for $99? Cheaper than an ipod and definitely more reliable if you are going to have it on 24/7. It would only be am/fm.
The problems with radio are:

1. A little less professional due to commercials.

2. More obvious you are not paying ASCAP/BMI/SESAC due to said commercials.
I ended up using a small mp3 player. Then attached it to a USB to 120volt wall adapter to keep it charged. Seems to work fine. $71 total investment.