No need for a remote start switch. I've started dozens of engines sitting on the ground using jumper cables and a screwdriver to trigger the starter. Touch the screwdriver between the big terminal and the start terminal.
20 seconds is long enough to listen for knocks and observe if engine smokes when you rap the throttle. It won't overheat in this short time. Also start it with the vent hose off the valve cover. If you can see any fumes come out, it is a sign of worn rings. A good engine will have zero fumes.
Place block of wood under back of oil pan to support engine
Fasten transmission and bolt up the starter. No need for a clutch
Fuel can, electric pump and hose to carb Jumper cables and battery Jumper wire to fuel pump Jumper wire to coil No need for water/coolant
Before starting, connect fuel pump to fill carb fuel bowl. Rotate throttle linkage. If it doesn't squirt gas (common with engines that have been sitting), use a puff of starting fluid, or pour an ounce of petrol down carb. Hold the choke closed while staring engine, or use your palm to mostly block the carb throat.