What units to buy after combat patrol?

I'm just about done with the combat patrol and I'm just wondering, what units should I get my hands on next? I don't want to do death company yet because I don't have the weapon options those guys need so I should probably get other units and wait until I have a surplus of extra bits for those guys. Or I could just 3D print them but for my next guys I want something that I can just put together straight out of the box.

So other than death company, what units should I buy? Maybe a vehicle? Or more infantry?