I don't want to but in, but a description of the track, lengths widths radius'might help people who have never race there give you some advice. Class weight would help too. Any variance in the rules, track specific, would be a help.
That will be some trial & error as this is the first year for them there, but based on gearing for other classes, I would start with a 21/60 and go from there, you'll only target 4850 RPM , I'd have 20 & 22 front drivers with me as well.