If you need fighting advice from guys on a video game website then I think your in bad shape haha. Anyways, your best strategy is one you've already picked. He's fat and out of shape, he won't last long. Good foot work with different angles should work well for you. Just don't get knocked out. I would say if you have any wrestling experience you could try a single leg take down, which could prove to be very effective if you can mount him.