The range on the stock Taigen or Heng Long IR system is about 30 feet. Tamiya is about 90 feet. This is the main reason that every club I've ever heard of uses the Tamiya IR Battle System.

As for good first tanks for you, you said mainly you and the wife, so first you have to decide IR or airsoft. It's not difficult to hook up a stock IR tank to be able to swap hull tops from IR to airsoft, but only certain tanks make good candidates for that. If you'd be happy with a pair of Tigers it would be very easy to do. If you want to go airsoft, most any tank will be a good choice, and it sounds like you have a budget for Heng Long. As far as I know there are no systems for two airsoft tabnks to battle each other, but you could maybe set up targets and do a number of hits competition or who can hit fastest or something like that. Here's a silly idea

https://www.youtube.com/watch?v=-GG5xV0SCUo But seriously, do you think you'd want IR or airsoft, now that I've given you the ranges?