on a crossflow, with a alloy sump, (i'll take pics) to what level should i fill the sump? its alot shorter than the standard sump - so i'm not sure if the distick will have the correct reading

untill i upload a pic its just a rectangular alloy sump

You still fill up to the same mark on the dipstick even with a shorter sump. Yes this probably results in less oil capacity overall but usually isn't a problem.

^ i agree with that. what you don't want is the crank hitting the oil in the sump as it can make it foamy. so you don't want to fill it any higher than the max mark on the dip stick