Obvious nids that are in are more than likely going to be the guants, warriors (possibly prime and shrikes) carnifex and hive tyrants. What other nids do you want to see in the game.
Personally I want to see zoenthropes, venomthropes, toxicrine, haruspex, exocrine, mawloc, momma tervigon, hive guard and genestealers in this game.

to be a bit blunt all of them, I want to see scenario's where we have swarms to kill , or just 1 epic nid, or a mix of both

The 40k universe isn't just about PvP, if you want to take a break from whooping Eldar arse, what better way to do it than 'nid on a rampage Even just the slightest bit of variation with greatly increase game playability imo.

Any kind of 'nid that can be barbequed like shrimps.

Any thoughts on the marinade you'll be using?

Trygon/mawloc, gargoyles, raveners, and tyrant guards. So giants, air units, ambush units, and tank units.

Only one I do not want to see is the pyrovore. It is hands down the worst unit in tabletop PERIOD. Or if they add it make it something of an encounter using it to kill the nids. Hive mind may be diverse and almighty but it makes some really big duds

GW knew that it wouldn't be loved so made sure each model had a hug

Biggest hug in terms of what use to be the WORST went to the you know whats that use to be a champion of chaos. They use to be even worse than the pyrovore till they got a 6th edition codex update and buffed from one of the worst (no one will take them) to one of the more handy fast attack units in the chaos codex. Hope they do not nerf the cs on updates (seeing khorne daemonkin I do not think they will be nerfed any time soon) sad for pyrovore is that is has a very good model.

I would use a garlic marinade

Always good, I'd've of gone for a sweet chilli.