Im hoping to find something...I have a gig 2-5-12 and its our biggest gig so far..id really like to get a good feel of the cab before hand..now just gotta decide against a 412 or a 410(with aspirations of getting another cab to stack on top)....now shall I look at 4 ohms or 8? What are the pros and cons with the gk700rbII amp in each of those ohms?
My friend, you've got so many threads currently going that all have the same theme.

The difference in sound/volume between the same cab running @ 8 ohms -or- running at 4 ohms (more wattage at the amp) is really small. Seems big on paper. In the real world... not so big.
But, with the amp you already have, if you get an 8 ohm cab, you have the option to add another cab. You don't have that option with a 4 ohm cab. And adding another cab WILL change sound/volume in a big, very noticeable way.
I've gigged a long time, and flexibility of equipment is my mantra these days. For me, the option of being able to use one or two 410 or 212 cabs trumps only being able to use one 412 cab. But that's just me.