Well, first of all, all the scouts got already a teleport homer to help bring the termies.
I tought putting the commander with the power fist termies squad, but the fact that he will not be on the table before the second turn, and leave all the scout with a leadership of 8 is suicidal as the scout will probably fall back and then won't be able to shoot the annemy afterward and will call the termies farther away of the enemy. So i'll opt for putting him in a corner of the table and maybe, if he come to near, use him as a bait to protect the vehicule.
As i dont like the marine with a save of 3+ i choose the speeder in the fast. They got a great mobility, got a great fire power and can wisthand some fire before collapsing.
The whirlwind will use his own guessing fire so i woulnd put him under enemy fire. As for the 2 predator, they'll serve as bot anti-tank and anti-personnal fire, all depending on the opposite army composition.
The dreadnought and 2termie squad will arrive inside the ennemy line and shoot. They'll probably get into HtH the turn they arrive and that's the real use they got. If the squad with the power fist are not in close combat, they'll serve as tank hunter if any vehicule are hiding themselve.