ok this is what i got from paint...since sketchup is bein a lil bitch atm
not sure if you're going to hear a difference between the 2. with the dimensions i PM'd you, they're very close to the same air space, and tuned the same. i talked to a 'reputable' (so i was told) audio guy at a shop, and he said it's good to make the boxes shallow as to give the subs a sense of being in an infinite baffle. dno if this is true or not...but i cant say he's wrong, so that's why the first box is so long and shallow. thought it'd be nice to have it right between the wheel wells, easier to customize as far as flushing it all together with trim panels.
the second box is deeper, and not as wide. the lines on top of the box is to show how the port would follow through the box. also, i read that it's a good idea to put the sub as far away from the port as possible. again i dno for sure, that's partly why i'm posting this pic/info in case anyone can dispute or back me up. if not, then feel free to put the sub anywhere but that's what i got, hope it helps with a visual at least