Tandem rigs are usually rated for 500# exit weight. The rigs themselves weigh roughly 60#. Total student/instructor weight can total 440#. Theoretically, you could find a 90# tandem instructor and fit this bill. I have never met one, nor would I recommend this route as they would have little to no control of freefall with your size in comparison. Alternatively, some dropzones have modified tandem rigs to allow students to jump them. Meaning you could fit this weight limit much easier. If you can find a DZ that has one of these, take a ground school class, and spend some time in a tunnel with an instructor. This also presents a problem as most tunnels have a 300# limit. You'll at least have to do some good negotiating with the tunnel staff to be allowed in, and you'll have to be trim enough to fit into one of their suits. I'm 6'6" 230#, my brother is a former right guard currently at 6'4" 320# and we were able to get him in the tunnel because he was physically fit, as most linemen are, and his height gave him a really large canvas to catch wind with. The trick to this is the tunnel time, most instructors will be nervous about keeping up with you in flight because you will fall like a bag of bricks. I am only at 230# and some instructors had trouble keeping up. Having tunnel time will allow both parties to trust you at least know correct body position and what to expect with regards to wind. This options requires a perfect match-up of DZ, gear, tunnel, and instructors. Long-shot, I don't know of any that could, but its possible to find. I would recommend finding a larger DZ with the equipment and a couple larger, accommodating instructors. Work with them on how to get a jump in. Being a "giant" usually helps when weight is concerned due to your ability to get big and catch more air. Your range of fall rate in the sky could be large due to your height. There's just a limit to everything. I would recommend getting under 300# and this task would be a considerable bit more manageable. If you make it, especially to your license, please write a post with pictures. I'm sure there a number of guys in your position.