All you need is a impact screw gun, drill, wood glue and screws If you buy the sheet of mdf at home depot, you get the guys there to make the cuts for you, its 50 cents a cut, first 3 cuts are free. Have someone you know with a jig saw/circle jig to cut the subwoofer hole, then its basically glue and screw then you are done.
The other thing you are lacking is square inches of port area, you are tuned in the SQ section instead of the sql/spl side.
Here are some free box plans that have cutout sheets for you to make the cut. Just figure out how you should cut a 48" x 96" sheet of wood to make the most out of the sheet of wood.
*OFFICIAL* Free Ported Box Plans (56k NO!!) - Dodge SRT Forum
whole thing shouldnt cost you anymore then 50 bucks to do.