I'd go woth a Futaba 4EXA or 6EXA..

Both have memory for multiple aircraft so you won't have to get another Tx anytime soon.

You can get the 4EXA from Tower right now for $125 using the current $25 off $150 discount code on the main page.
Or the 6EXA for $155 using the code..

If possibe I'd get the 6ch radio.. It's only $30 more and will let you play around with flaps, bomb drops or do an easy milti-servo aleron/flap setup on your next plane..

I remember when I started out with a basic 4ch Tx.. 6 months later we picked up a a 7ch system.

Whatever Futaba Tx you buy you should get a 127DF 7ch Rx with it so you could pickup a 7C down the road and all your current flight gear would be fully functional with it.