Devs are always a solid choice, though their main drawback (cost) is compounded with Blood Angels.
Going with mixed weapons and combat squadding them is a fun idea, effectively getting two different fire support units for your buck. however, in Escalation games that squad is going to have to deploy from reserves, which means they'll come mixed together and you can't separate them. Which means half the time you won't be getting th most use out of the squad.
If you're like me and play mainly friendly games with people who all hate Escalation, then it shouldn't be a problem. But in tournies and the like it could be a pain in the ass.
Four Missile Launchers is a good solid unit. It can tackle heavy armor and it can pepper troop squads with frag. And you can still split them up and have two squads with 2 launchers each and hit different targets.
However, don't neglect the tanks. They're pretty cheap and they give you mobile firepower (which fits very well with the BA theme). The Baal predator is an excellent heavy support unit, particularly if you're a little low on anti-troop. Otherwise, Annihilators with heavy bolter sponsons are a good choice.
I prefer not to take laser sponsons. They're too expensive and if you move you've wasted points.
Vindicators are fun, but realize you;re basically buying a 125 point decoy. Every gun is going to go after it, so use it to draw fire away from other units. Unfortunately, our extra armor upgrades cost more and, appallingly, they didn't give us Machine Spirit as an upgrade option! So the good ole Doomshovel is going to break very easily in a BA list.
but it's big and it;s scary, so if you have a bunch of melta bikes or some fragile transports, throwing in a vindicator is a good way to keep those weaker, high-priority units alive long enough to do their job.