I would take the 152 or the A8, depending. I usually took the 152 unless I knew for sure the bombers were not above 20k, then I'd take the A8 with her 30's.
Regardless of which gal I took, I took 100% fuel every time since intercepting bombers can be a long process, especially against those who were willing to stick around and fight it out.
Convergence I'd set to 400, pushing it out to as far as 600 on the 152 at times.
I was more and more using the 152 though, as she has WEP for ages, climbs like a rocket with it, and had little trouble up high. Plus she had some good power with her guns. I was getting to the point of where I wouldn't let my tail slip out from under me while making some pretty hard maneuvers, or if she did, I could recover fairly quickly and resume the intercept. She's a joy to fly though, and can fight it out better against another fighter than the A8 with her 30's.