I agree that one troop choice won't cut it, in fact it's not legal as per the force org chart (if your mates let you field it then that's fine).
I am a huge fan of the Infantry Platoon. Not sure if you're aware, but even though an Infantry Platoon is a single Troops choice, every element of the platoon is a separate scoring unit in it's own right. I played yesterday at 550 points and had a platoon and one Veteran squad, for a total of 6 scoring units.
If you can't change your points around for that, that's fine, but I do recommend them.
I would drop the Stormtroopers at the very least, they are very underwhelming on the tabletop. Pickup another Vet squad; not only are they Troops (to satisfy the minimum force organisation requirements for a normal game), they are also quite good
The vet squads should be setup with specific roles in mind, and they need to be mobile (meaning no heavy weapons).
I like fielding two vet squads supporting my Platoon:
Vet 1, anti tank
6x Las Gun
3x Melta Gun
1x Sgt (with Melta Bomb or Demo Charge)
Vet 2, anti heavy infantry/light transport
6x Las Gun
3x Plasma Gun
1x Sgt
These guys come out of my Valkyrie's/Vendetta's, and make a mess wherever they go, while my Platoon gun line sits back and shoots.
Some food for thought at least