Steve, have you tried some of the Hawk pads, up around the HT70 compounds???
I used them in my 2B car on the front with 4 spot dynalites and vented TP Magna rotors. Different rules I know, but the pads may last the round as I used to get half a season out of them on the Sydney tracks.
They were harsh on rotors though, a rotor would last two sets of pads comfortably, and could squeeze a third set of pads depending on where the races were as the rotors would get very hourglass in profile and start to get a lot of fine cracking in the surface and obvious hot spots.
It maybe an option to throw a set of the Hawks on with a fresh set of rotors and see how they go for a weekend.
Dead easy to download the Hawk catalog from the website to peruse the different compounds and also better to purchase from www.hawkpadsdirect.com The price for two sets delivered will be about the same as one set from local suppliers even with the crappy exchange rate at the moment.
The tech guys are very helpful also, if you want a contact I could dig up the email address of the guy i dealt with when trying to sort out what pads to use in my old bus for you.