I just got some nid models from a friend and plan to make 2 matching armies just for dueling each other. I'll probably use them for pickup games when someone wants to learn 40k or hasn't got an army with them. I have practically all marines units available already, so the challenge is to make them evenly balanced. The nid army will be very mobile, while the marine army is fairly static.

Strategy is to use the tac squads and Dread as a mobile fire base. Devs and scouts will infiltrate into good firing positions and shoot the whole game. HQ jumps around and supports units that are assaulted. One tac squad is extra big, this is probably the squad the reclusiarch will join. Any improvements would be appreciated.

Archer Chapter
[See, but not seen. Die Standing]

Reclusiarch BP, Jump Pack, Thonors

Dreadnought AC

Tactical Squad(6) PG, HB
Tactical Squad(6) PG, HB
Tactical Squad(10) PG, HB
Scout Squad(5) ML, 4x Sniper Rifles

Devastator Squad( Infiltrate, 4xML

Total: 1005
36 Marines
2 Vehicles

I'm making a similar post in the nids forum to improve on that army, here's it's prototype for reference:

Flying Tyrant Scything Talons, Toxin Sacs, Wings
Broodlord Extended Carapace, Toxin Sacs, Flesh Hooks
3 melee warriors Rending Claws, Extended Carapace, Leaping
17 stealers Extended Carapace
20 spinegaunts
12 hormagaunts
3 raveners
Total: 1000
56 bugs
1 MC