31's are bearable with stock gearing and a 1.6
I drove mine like that for a week in while i was waiting to put my gears in...
Bottom like its though, for the sake of $6-700 your better off getting the gears straight away.
30's will drive better but what happens a month or two down the track when you get your reduction and want to go bigger again...
My opinion is wait until you have the money for it all and do it all at once... much better outcome
