Righty,

That radio will do the job for now but does not look like the most bang for buck.

Dual rates
Travel adjust
Sub-trim
Servo reversing
3-model memory
4 types of preprogrammed wing mixes (standard, flapperon, V-tail, or delta/elevon)

3 model memory seems a little low with the next plane you will fill the space and looking for a new radio. Which will happen quite soon as this is an addicting hobby.

wings sugggestion Futaba 6EXA is good radio and will do the job for the most 40-60 size planes and is a perfect step up from the 4ch basic radio, but it is Futaba and you probably want to stick with JR since you have already JR stuff, I use Futaba and don't want to give miss information about their models.

You better check with the radio forums and do a search here for jr 6-8 channel radios, you might find a perfect 6-8 ch JR system for the long run.
Looking at Horizon web page http://horizon.hobbyshopnow.com/prod...Prod=JRP6644**
seems like a better investment.

also you can look into Hitec 7ch http://horizon.hobbyshopnow.com/prod...prod=HRC171721

which is a good radio.

but $50-60 more than what you selected but seems to me like it is worth, you are the end user you will decide what you are going to do with it and how much you want to spend. Are you adicted yet? if yes go buy the good one you will soon need or just want to have it.

You can still use your current radio for the two planes as described above by Crashem.