1 each 5 man scout team
1 each 5 man jump pack assault team
3 each six man tactical teams
1 each Commander
1 each Rhino
BR will give me some Terminators, a Dreadnaught and more marines. I am looking at a Land Speeder, but my budget and lack of experience are limiting me.
Well, add another 5 men Assault squad. This gives you a 10 men squad; give the Vet Serg a power fist.
Moreover, you need more troops. At least 2x10 Marines, equipped with flamer, missile launcher; power fist for Vet Serg. Add two Razorbacks.
The Commander is fine.
Next I'd go for a Sternguard unit; you could play the Commander as Petro Kantor, Sternguard will then count as troops.
Finally add some support units. Personal preference here. Shooty Dreads, Termies, Predators...