It 's a shame that the 6x6 tiny variant doesn't exist. ;)

I like Fast Espionage the most (yup, with the volcanoes), or Open Small Espionage.

For time control you should have the vacation on, as the new format only allows 45 vacation days (60 if they would pay another membership) . If those are all gone, that's over for them. It's fair to assume that players visit the site daily, so use a fixed time per turn, say 1,5 days per turn. If you hate the vacation system, do fixed weekends only or even no days off.