First, I suspect towing would put you over towing capacity for the mini-van. A civic weighs about 3,000 lbs, and the towing capacity for an Odyssey is 3,500. However, that does not include total payload, and presuming you're going to have the van, and possibly also the car packed with stuff that's being moved, it would be very easy to be well over the payload capacity for the van.
Tow dollys are also kind of tricky anyway - for example, you can't back up at all - and if you don't have a lot of experience towing, it's probably a bigger challenge than you need.
Even if you weren't at towing capacity, Towing that far also is likely going to put a fair amount of stress on an 8 year old minivan. At that age, the van is probably getting to the point where you've probably got some parts that are reaching the end of their expected life cycle that would need to be repaired sooner rather than later. Not a deal breaker by any means, but also a factor worth considering.
As far as radios, I would generally agree with Buck. Years ago, they were a good idea, but with cell coverage being nearly universal on interstate highways, I don't think there is a need. All you really need is to be able to communicate when and where you're planning your next stop, so even if you hit some pockets with poor coverage, you should still have plenty of opportunity to coordinate those stopping points.