But generally, in the upper 9's for SCR is where I would head just at first guess based on other motor work. Are you going to run that Sniper system?
BTW you can take your static CR and the cam specs and work through any good DCR calculator and look to get a DCR of high 7's to 8. The trick is to interpret the Opel cam specs, which give duration as seat-to-seat, but you need more like .006" lift duration numbers to get an accurate DCR. (The .006" number is for a hydraulic lifter cam; a solid would be different.)
Just be aware that your rod-stroke ratio is getting low, down close to 1.5, as opposed to the stock 1.9L rod-stroke ratio of 1.8. So it will be the typical low rod-stroke ratio stroker.... it'll not rev as high before starting to flatten out. (There is a reason that a 2.6L Misubishi kept a longer rod and deck height...to keep the rod-stroke ratio up.) So, you'll want to keep the low RPM torque good to keep a reasonable total RPM range. Of course, 2.6L in a light GT will no doubt move along.