I'm not an expert on this subject. But you could take a look at a class ab power amplifier as used in audio amplification. They are made to deal with very low impedance and high output current to drive speakers. 

Something like this: ![class ab power amp](http://m.eet.com/media/1063371/LiFig13.JPG)

Although you should probably check whether your transistors can handle your frequencies.

[Image reference](http://www.eetimes.com/document.asp?doc_id=1274753)