My 7-button layout was alread on the SFII control panel when I got the cab (below- unfinished WIP), so I went with it. After setting up the controls, I'm not too happy with the way the games play. I play mostly SF type games and NEO GEO, so I was pretty pumped when I got the cab. Anyway, this is what the current layout looks like:
X
    X   X   X
    X   X   X
Does the button layout below make sense for Street Fighter games and Metal Slug??
4
    1   2   3
    4   5   6
To my knowledge, the 4 button on the top isn't used all that much for the NEO GEO games so that should work (?) I didn't want to make the ofset button #1 because it doesn't feel too comfortable extending your index finger up for an extended period. Also, would the bottom 6 buttons setup the correct punch/kick layout for SF (light --> heavy)? Any input is appreciated. 
PS: there was alot of info on this when I searched but it was all for the 7-button layout with the extra button on the bottom so it wasn't really all that helpful.