u/NieA7

I recently bought a heavily discounted "Starter Set" to play with my 8 year old, as I like Nighthaunts and he likes the Stormcast Eternals. We've played a few games and had fun, I'd like to get some more warbands to include my 12 year old as well but I'm confused how to build out from here. I think this version is quite out of date, so...

If we got the latest version would anything from this starter box be usable, or would it effectively mean starting again?
If we stick with this version, is this "starter set" the complete rules or is it stripped down in some way?
If we stick with this version I imagine you can only get warbands and their cards secondhand by now, is there a list of compatible ones somewhere I could check?

Sorry if this is a stupid question but I've not been collecting for a long time and I don't yet understand all the Primaris stuff.

I've got a 5 man Deathwatch Veterans kit still on the sprue, but as they're probably going to be retired I'd prefer to build them as an Aquila killteam. I don't mind running firstborn as Tacticus (if that's the right term - just normal marines), but the Gravis guy makes things complicated. I figure there's probably cheap marine bodies being resold from the Armageddon box, but I don't know which of them match to what roles in the killteam.

If I bought one Aqulia team what's the maximum number of teams I could make with appropriate weapons if I used all the weapons from that and the vets sprues, and what additional bodies would I need to get above and beyond what's already there?

(I've also got two of the mini-of-the-month Deathwatch guys if they can be used.)

Where to go from here

Kitbashing Additional Aquila Teams