91 240sx hatch box help

so i got a deal on a 91 240sx hatch its in perfect shape and runs great for $1000. my dads racin buddy has to many cars so hes hookin me up. it'll be a couple weeks b4 im able to get or see the car in person cause im waitin on my lawyer to call me and tell me to come get a check. so i've been googling and youtubin all day and i can only find 1 with a real system and its walled and im not wall reaady lol. so i come to you guys for help cause i know someone has or knows someone with a 240 and a system. i am wondering if i have space in the hatch area for a good 4cu ft. box after displacements kerf ported and tuned @ 33hz for my rf power hx2 15 powered by my saz1500. so im thinking sub up port back or sub and port both faced towards back until i get some cash saved up to buy multiple 15s, 18s for a wall since i got a job finally. any help would be much appreciated links, pics, vids anything so that i can have my box plans ready for the day i get the car and yank everything from my current car and be bangin in the 240 in 2-3 hours. also would like to know if the stock electrical in the 240 is strong enough for the saz1500 with the big 3.