I have 300l multispace set up, you def need to have the double seat down to fit a tank in, but i guess u know that.I have a "D" SHAPED TANK WHICH BACKS RIGHT INTO THE SPACE CREATED PERFECTLY. ALSO PLENTY OF SPACE FOR 75AH BATT, HOSE REEL,WARNING CONES AND 25L BUCKET.VARIFLO AND PUMP ARE MOUNTED ON THE PANEL ON THE BACK LEFT SIDE . i will try to borrow my bros digital camera and upload some photos. prob wont be for a couple of days yet.