It has been a little while since i fielded then as squads but I usually put one in a vet (harkers) squad.
Autocannons and las cannons are big.I'm sure the math gurus will be here shortly to tell you what to take and how to play them. as I play for fun, I dont do the same thing every time and dont profess to be an 'expert".
A few tips to help you save some money and help you get more bang for your buck from thactual models though...This s what i did.
Got a bunch of extra horse bases, got a bunch of extra 60mm
HW bases, got a bunch of extra 25mm round (infantry) bases, terminater bases and spare guys standing up along with rubble and other items about the height of the tripods.
1. I put themorters together and put them on terminater bases.
2. The missile launchers, i mounted onto spare guys standing up so that they are firing from the shoulder standing.
3. the tripods and rubble pieces, I mounted on the horse bases so that I could then glue the other heavy weapons onto them (autocannons, heavy bolters and las cannons). I did not attach the side batteries or ammo. Those i suck in my bitz box or added to objective counters.
4. I seperatedthe croching guys ito gunners and spotters. the spotters are pointing and the gunners I put together with the grips/riggers in their hands and stuck both on 25mm bases. the triggers, i conser to fire the guns remotely.
when i use a heavy weapon, i just stick whatever combo i need to use whatever weapon I need onto the empty 60m
HW base. This will even let you field more at a time per box bought, if you mix in standing guys to use as gunners/spotters (sometimes good to do anyway as they stand higher and allow the team o see better.
autocannons seem to be the new "in"
HW nowadays so likely you wont have many spares of those. In case you do get your hands on a bunch of extras, they can be converted into ripper guns to put onto fantasy ogres to make MUCH cheaper ogryns. I have pics of a unit of them plus instructions in my gallery.
Good luck and welcome aboard the guard train.