Mamba + Rustler = Which?

Next month is my anniversary and my wife will be getting me my first BL system. I've decided to BL my Rusty before the maxx since she is paying and the maxx setup I want is just too much money to ask her to pay on her salary.

I'll be ordering a Mabma Maxx system from Mike and I'm just not sure which.

I've read up on them all, I understand the cell count limits and that the 5700 will be a better choice for Lipo.

My wife will not let me go the lipo route while we live in our current shoebox, but when we move to a larger place the sky is the limit (or my pocketbook anyway)

I've already ruled out the 6900, so it's a toss up between the 5700 and 7700 systems. Being that I run 7 cell zapped and matched IB4200's I'm leaning towards the 7700 as it will get better performance on nimh.

I'm not a racer, just a basher but I worry about the 7700 cogging. I've read alot more horror stories about cogging and frying 7700's than 5700's.

Should I not let this be a concern since I run high quality nimh packs?

Should I get the 5700 and just deal with the slower speeds for a year or so until we move?

Should I get the 7700 now and when the wife lets me go lipo buy a 5700 motor?

Should I get one of Mike's nifty motor clamps to go with it?

Thanks for your input and assistance. Mike, be on the lookout for a MM + castle link purchase the middle of next month!