The S241 servos that come with this are 9 gram sub-micro servos with 17 ounces of torque. The R610UL receiver is not in a case at all, it is just shrink wrapped. So, the receiver and servos are more suited for something like your SuperCub and not a Tower Trainer or Superstar. The transmitter looks like a very nice unit and is probably worth the 90 bucks by itself.

To buy the ebay radio, a full range flight pack, Tower ARF, and engine would cost at least $375.

The Tower RTF is $279.99 and there is a discount code for $25 off a $200 order. It does not come with a fancy radio but it is perfectly good for what it was designed to do.

I'd buy the RTF and start flying it. I'd work with an instructor for a while. Even though you're already flying the SuperCub, an instructor will be able to give you lots of help and advice about safety, engine tuning, trimming the plane, etc.

While you're flying the trainer you can figure out if you want to stay with 72 mhz radios or go to 2.4 ghz. You can decide how much radio you really want and then decide which brand and price point to go with. By the time you are ready for the next radio, there may be even more good choices and better pricing.