What's the maximum number of moves possible?

If you asseble the white team as you want, for example replace every pawn with a queen, and place every piece as you want. The only black piece remaining is the king.

What's the maximum number of moves the white can make?
I need to know if it's impossible for any team to choose between more than 147 moves. (Do not care about whenever the black team is check mated or not)

Reason I'm asking is because I want to know if I can use a byte or int in my chess engine.

In this position white can play 218 different legal moves.

But how could the position on that diagram have been reached? I don't see a legal move preceding that position.

On the move preceding this one, black played b3-b2.

Thx! :) Then I'll use a short... :(

I'd say 99% of positions have less than 50 legal moves for one player -- if you want the engine to only handle practical positions whatever you're setteling for you wouldn't have to -- although I wouldn't know where to begin programming an engine so maybe I'm way off...