Dan,
26 psi front, 23 psi rear at most! Start there and check after first session. At 40 psi, you will be sliding all over the place.
Cheers, Pete
PS You are right the BFGs are dogs but good to learn on cuz you gotta have the right line and an easy touch. The good news is that the BFGs will give you more warning than the slicks which will hit and pass through the limit of adhesion with little or no warning. After you get some track time with the BFGs check out the Goodyear Cobra tires through Roger Kraus racing.
http://www.rogerkrausracing.com/