[jcunning]

I don't have actual experience with installation, but I have spent enough time investigating the different systems to offer a little bit of advice.

Make sure you have a local contact for troubleshooting issues. You don't want a system where the support is in different time zones. This makes is very difficult to work through a hard to diagnose problem.

Be sure to line up a local Dyno place to dial in the system. No system is perfect out of the box and there is about 5-10+ hours of dyno time required to make sure everthing is good. Also be sure to budget the dyno time as well, it's not cheap!
You can try to use a friend and a laptop to dial in the car, but this is much harder due to speed limits and traffic.

Hopefully you are a technical, computer savvy person. All of the systems usually require some type of laptop connection for code uploads and system tuning.