High current from an op amp with or without transistors?
The sine wave is max 30V p-p (Amplitude=15V). Max freq. is around
  1MHz. The setup currently being used is ADA4077-1 with gain of 50.


The ADA4077-1 has a gain-bandwidth product of about 4MHz so, with a gain of 50, the bandwidth of the circuit will only be about 80 kHz - this is the first problem to solve - you need an amplifier (before the output driver) with a GBP of at least 50 MHz in order to keep your frequency response level up to 1 MHz.

I'd seriously consider looking at something with a GBP of 100 MHz minimum for this. What about the AD815: -



It looks like it can supply the current, can be paralleled, can produce 40Vp-p and has a GBP of 120 MHz. I'd also look at what LT have to offer.