Hey Dave. Well....if you are cutting wood, it is going to take a saw. I would use a combination of circular, jig and reciprocating saws. I would have a helper use 1 or 2 shop vacs with a nylon over the exhaust vent to control the dust from being blown into the air. Any saw dust that still occurs should drop down to the floor where if can be cleaned up. I would think this approach should keep dirt to a minimum.
Go slow and cut straight lines to avoid excessive sanding later.
Regardless, unless you have access to a laser, you will get some saw dust to deal with.
Donald
