It all depends on if you want a wheel for downhill,grippy; a wheel for sliding, obviously not grippy; or an all around wheel. Beside that, it depends on what board and trucks you have because you may experience wheelbite. I personally like 70-75 mm wheels. For downhill I use Retro Big Zigs (lime) and for sliding I use Hesher Snowballs (extremely slippery).
Chicken nuts
Spitfire wheels look the best....
purple orangutans are good
Yes, just swap your bearings from skate wheels to longboard wheels, its all the same.
A longboard or hamboard.
depending on the sises of the wheels will shrink
depends on how used and what brand and model of wheels.
Buy wheels, trucks, and a deck and screw them together
e-bay
The shape of a longboard was invented before but the trucks and wheels were small like those of a skateboard. Early boards didn't have pop.
It doesnt matter it should just fit
You can use a longboard on any type of wave but gently breaking waves are best.