I am glad to hear that you are continuing to make progress and hope that my input has helped.
Continuing more into the devastators however if you are going to be drop poding them I would highly recommend giving 4 of them grav cannons, and maybe a combi grav on the sergeant. Reason being is that grav is king right now, and if you put any other heavy weapon we have access to on them in a drop pod then once they disembark they are firing snap shots, due to them being heavy weapons, meaning 6+ to hit if it is not a template weapon like a plasma cannon, if it is a plasma cannon them you cannot even shot it immediately.
Going more into the codex seeing as however you NEED this as the changes from 6th to 7th edition for DA makes everything viable unlike in 6th, for example our flyers are also relatively solid now a days as the can carry around what is basically a vindicator's demolisher cannon, and has the potential to be Strength D. Another amazing example of changes from 6th to 7th is that green marines are a very solid choice for the core of your army and everything can now fire overwatch at BS 2, which can be modified to BS 3 and even an unwieldy FULL BS IN OVERWATCH. HQs are very good too, while our named characters are not the best some of them are very good Ezekiel is still a monster along with Sammael in both varients, even generic HQs are good as almost all of them minus 1 are fearless.
Hope this helps.