I'm a one person operation and know several other racers like me. We race Burris SS33A's and fortunately for us this is the tire that Burris is focused on making along with the outlaw kart lines. If you're looking for SS11's or 55's it sounds like it will be a long road. Within the past week I've seen no less than 15 sets of brand new 33's for sale by individuals. My local kart shop had 33's and wheels last week. Palmetto had wheels for at least a couple of weeks. Sure I had to pay a few bucks more per item over last years price but nothing that I felt was out of line with the cost of everything else I purchase.
When you see "teams" that maintain their equipment (bearings, chain, clutch, engine, etc) finish ahead of the guy who races every week but hasn't cleaned their kart in a month nobody bats an eye. If the back runner complains that it's not fair they don't have the same equipment as the front runner they'll be told to put in the work and maintain their kart. A similar message applies to procuring wheels and potentially tires if you're on 33's. You have to put in the work to find what you're needing.
Slick27 is on point when saying to have fun and race within your means.