Lowtimer,
I did a pretty comprehensive study a couple of years back and shortlisted 2. GQ (UK) and Para-phernalia (US)
As I wanted a back-pack as opposed to a seat pack or half and half I opted for the American rig. It is one of their wedge shaped containers and as it is so comfy I have never flown my Pitts without it!
I met Phil Silvers (IAC Parachute guru and spoke to him at great length about my requirements) ie - I want to buy something I never hope to use!
Collected my 'chute on a trip to the States and all in all it was a couple of hundred quid cheaper than the GQ model from RD Aviation.
Hope that helps,
Stik