You can do exactly what you're talking about. Mainly, you just need to have the gas tank above the carb and let it gravity feed. I'm not sure exactly which carb you have, but most "pumped" carbs like what you're talking about is being done via a vacuum source. Not knowing exactly how this is with your carb, if you can find the diaphragm pump and block it from working, then put the gas above the carb, you should be able to run the carb you have now. You might even be able to do it without disabling the diaphragm pump.
If there is an issue with your carb and it doesn't work at all, you'd need to measure the base attachment area, the venturi opening, and bolt spacing, then cross reference that online to find what you're looking for. There are a lot of sites which sell carbs which also have these mounting specs for the carbs they sell. About the only way I can think of to get you what you're looking for. The only problem you might run into is if a carb you find is not big enough. This might keep it from producing maximum power. It really shouldn't be that big of an issue, though. You should be able to find something.