I've been fishing the short rigs the last few weekends with good success. The best rigs have been to the east and the closest one is about 8.5 miles, from there you can "rig hop" to the other wellheads close by. The snapper have been non-existent until you hit 75 foot deep, the closer rigs are in 50-62 feet of water. The snapper I have been getting are mostly undersized with a few small keepers, better chance of catching some kings downcurrent of the rigs/wellheads while bump trolling ribbonfish. Run two rods out, one with a 1.5 ounce weight (100 feet) and the other without weight(150 feet) and troll at slow speed past the side of the rig. After your baits pass the rig downcurrent, take your engine out of gear to allow the baits to sink for a couple of minutes. Kick it back into gear and get ready for the hit.
As for your fuel, 40-gallons should be enough... just run your engine at cruising speed (3800-4200 RPM) for the most range.