Just use windshield washer tubing it is like 3/32 size, nice and small
You don't have to worry about any real fuel resistance because you shouldn't have fuel going in to it anyway if everything is working properly. The occasional overflow or maybe sticking float wouldn't be an issue as it is not even nearly sustained exposure that would break down the rubber
Go to autozone, NAPA, whatever and get some cheap tubing and save the rest of the money for going fast