Thanks for all the ideas. I'm going to start thinking about making a hopback with a jar. I figure if i got a big enough container I can put the pellet hops in a bag, in the jar to help with containing the material. If the jar is big enough there should be enough liquid to keep things flowing.
The system I am using is the 60L pilot system from the local Brewery here in town. They have generously lent it to me as they are too busy to be playing around with new recipes right now. It is modelled very closely to their full size plant so the procedure on brew day is very similar. When I asked the brewer what he would do to increase aroma he simply said "dry hop it"....too easy!