Be a torque monster with the snail. Unless you plan on doing some major homework I'd skip the turbo. There are not many turbos out there small enough to use on a single cylinder engine and unless you plan on building a fuel injection setup it's gonna be hard to control the boost and fuel ratio.
I'm all about weird and cool engines. Heck I have a history of building chevy 60 degree v6s, inline 6s, and even a single inline 8 to whip everything in the 1/4 mile. A single piston oil burner with a snail is gonna be a money pit compared to the power gas burners make out of the box. You are gonna be one off everything with it and it's just gonna keep adding up. I can tell ya I put a small blower on a 250 chevy inline 6 and if I would have had to price out the custom machine work that alone would have been stupid. Even with me doing it I spent more than a built SBC would have cost to build and made less power.