Handle placement

Ok im probably going to go with design c for handles on the mt121's i ambuilding. Does any one else have any good plans for handles?, i would love some cool looking ones for my boxes!. My question is though, "where do i put them on the cabs?". The red x on pic 2 are where i thinki will place them. The blue x im not sure about! as this would mean a change to the size of the rear chamber, would this effect performance for better or worse?.