RE: Ampeg v4 cab. what to mix with 2 greenbacks?

I recently acquired a 1970's Ampeg V4 4x12 that already has 2 Classic Greenback G12M's(25 watts) in it but still has two mpty holes.  After much research/ debate I have narrowed it down to mixing with a pair of either Reapers, Reapers 55's or ET65's. I typically will be playing an Orange AD30 or 70's OR80 through it. Also, should I mix these in an X pattern or top and bottom?

 Any input would be much appreciated.  ps. Any chance there is a new years sale coupon code coming? 

pss. Side question. Is it common or have you tried a Reaper/ Black & Blue mix ever?

Thanks-

Cool, cool, cool!  Hope those orig Green backs are good & healthy!  I'd pair them with the Reapers ... but if you want to hear a little MORE of your vintage GB's, then go with the slightly quieter ET65's!  Put the old GB's on top if you want to hear them the most :-)

And yes, the Reaper/BnB mix is fairly common ... and gives a VERY warm, juicy sound ...