For gravel? I am guessing the deep/wet snows are the worst? Two stage snow blower. Like Giles said, either weld some skids on the bottom or some have adjustable runners to keep it an inch or so off the gravel. Light/fluffy snow shouldn't be too bad up to the 3-4+ inch mark where the 2 stage comes in handy. Single stage snow blowers rock on lighter stuff but suck on the wet/heavy snows generally. On gravel they can be finicky. Better keep them off the gravel or you will have a rock flying at light speed before you know you touched the stones with the paddles.