Without doubt making your own is good way to go, it will at least work with the space you have, and getting creative with storage solutions, rather than having to compromise and use infills, spice rack's or dummy panels to make it work.
I've been fitting a Howdens handle less one over the last few months, piecemeal, huge list of issues that I've had to overcome, along with a stack of parts we didn't even use, client got a £1500.00 refund when he took them all back.
Personally I wouldn't use MDF for carcasses, I prefer Ply, with a couple of coats of Tikkurila's, clear matt, Kiva 30, not keen on MFC, but at a push I would use it.
But, do you have the room and the strength to be shifting and swinging 8' x 4' sheets around, getting them on to a table saw and running them through will be an absolute pain and you will need space either end, so at least + 20' to be able to work, a track saw is the best option, take the saw to the wood...
Then the other question is what do you do with them once you've built them, this is one I did a couple of years ago, storage space was a bit tight:
Another couple of points, I make mine at 800mm tall rather than the <>720mm standard, better utilisation of a sheet, and I use the Axiom adjustable legs, easier to set up and adjust with the long arm gizmo that you can get.
The Blum config system is ideal, for setting out and getting your material schedule, but it does take a bit of working out.