Pros: They can go where outboards cant touch, you dont have to worry bout clogged water pumps, and they are fun to have.
Cons: Mud motors are slower, harder to drive, louder, and you will be more likley to kill yourself once you see where it can go
Sand will eat up a prop in no time, you have to watch out for that and make sure the water is deep enough the prop doesnt come into contact with the sand
Longtails are direct drive. no neutral, no reverse, just forward.
They are harder to drive and tune in, slower than surface drives, but cheaper than a surface drive.
Surface drives can be belt or gear driven and have several options like nuetral, reverse, and power trim. They are fairly easy to drive, can go up to the low 30's.
I suggest a hull built for mudmotors if you want the best performance
If I were you a 17x54 and 35/36 hp surface drive would be my choice.