Hmm...  The Aurora class isn't that bad.  It has ridiculous shielding and the drones could annihilate just about anything but... The Aurora wouldn't be able to replenish its drones.  I'd also hope to avoid having a ZPM unless we find a good story reason to have it.  (Like at some point an antagonist steals it)

The real problem would be the Ancients themselves.  We know little of their culture and their science- well, they know how how everything works!  

I'd recommend an old Aurora class ship inhabited by "The Travelers" or SGC personnel.  I'd further suggest the Travelers since they could work well with those aboard the BC-304 since the SGC/Atlantean personnel would know how to use their ship better than the travellers would.