Was playing around with enclosure design calculator last night and came up with this for a starting point. To clarify, I've almost never ran ported boxes (bought one like 12 years ago for a eclipse 15 and a few years ago for a different set of idmax 12s). Because of this all the issues that are common for ya'll such as port noise and how much port needed are all unfamiliar to me.
Shooting for 2 cubes per sub and tuned at 32hz. Dimensions are 34" wide 14.5" tall and 22" deep whihc will net me 4.22 and leave me just under 4 cubes total after sub displacement. slot port with dimensions of 4" wide and 17.25" deep at port wall one and then a right turn of 2" to get to my desired 32hz. This gives me 13 sq in of port per cubic foot which depending upon who you listen to falls right into the desired range (read some that say 8-12 and others that say 12-16 sq in/cube required).
Im not above paying someone for a design enclosure but like to do stuff like this as a way to help myself learn. If Im way off base though please let me know and maybe I should hit up a designer.

amp is a jbl gto2400 at 2 ohms so each sub will be a tad over powerd but Ive ran them this way before and they were fine. vehicle is a 05 silverado ext cab with no back seat.