I have a Friend who plays Necrons, and this is how he built his IG allies. He is a desperate alliance, so your Unit can even score!
Ministorum Priest with Eviserator-60
Veteran Squad with 3 Flamers, Shotguns, Powerfist-100
Vendetta Gunship-130
Manticore-160
It is only 450 points, the Manticore hides behind any troops you leave at home, and hopefully in good cover. The Same Ruin you bolster and put hte scouts in you can put hte Mcore behind. The Flamers and the Priest go in the vendetta, which Zooms on the board and fries seomthing, next turn you enter hover mode, drop in the flamers, and burn someone off an objective, while putting yourself in cover. IF someone tries to assault you off, you have 3 flamers for wall of death, and 2 Power Fists! and if they dont finish you, you can flamer, shotgun, charge, and get rerolls.
In order for you to make this, all you would need is to convert the seargent to have a Power Fist, the Company Commander an eviserator, turn the meltas into flamers, and get a Mcore.
Even if you are a terrible converter, and don't want to do the priest, the Infantry Box and Company Command Box should have 3 flamers in it, and the Powerfist, so you can just buy a metal priest if you want.
He has used this against my IG (i was actually providing him the models for it) and had i not luckily, and i mean LUCKILY, shot down the vendetta (one Plasma Gun fired up at it, rolled two 6s to hit, two 6's to pen, he jinked one, and i exploded it) i would have surely lost my main objective. Add in the fact that for your army they can score, and i would say this idea would work great for you, because you get all the big bang of IG, for a low points cost.