Lipo saddle or shorty?
 

Is there any advantages or disadvantages between these two types of batteries?

I currently use stick packs but am thinking of going 4wd so my batteries would be no good. I fact I'm thinking of getting an Associated 2wd B5M and the 4wd B44.3.

Both these cars can use either saddle or shorty so which would be the best to go for?

If your cars will take any battery, there is no real disadvantage to any of them.

Only advantage with shorties is the ability to adjust weight distribution (or reduce weight)