Maybe you can find someone on here with an AM/FM/Cassette radio, and just use a cassette adapter to the iPod. Otherwise, I believe they do make iPod ports you can wire into the back. They run upwards of $40 and actually play through a designated radio station. However, you could get an FM tuner for your iPod that's cheaper and plays surprisingly clear through the stock radio. My iTrip works very well, and I was contemplating this before too.
I've never done it with roller rockers, but I have yet to do any major engine work on the Eagle. I doubt it would give any kind of noticeable difference in power, and it could create more stress problems in the long run. Although, it might be safe or necessary if you do upgrade to a more aggressive cam. You just might have to worry about things like valve float and bending pushrods. I think stronger springs would be a sufficient upgrade with the new cam.
The only thing I can think of that will add more power to the stock engine is to build a stroker. There are a bunch of members on here that can help you with that. Nothing else will give significant increase in hp without changing the look or getting rid of stock components. Ways to increase hp would be: ignition upgrade, 4.0 head swap, fuel injection, high flow exhaust, stroke the engine, manual trans conversion, change the differential gears- Not all of the ways, just the most common.