As others have said more information is needed, although most of it can probably be figured out by knowing you are just using the figures from Assault on Black Reach. Big Shootas and all Slugga Boyz as Troops, Twin Linked Rokkits on the Kopptas, etc...
Deff Kopptas will Have twinlinked Rokkits. If you can do some customization you may want to add a buzzsaw or two, just in case you get stuck in combat.
I imagine that the Nob Squads will have a few Power Claws. I would suggest picking up a Painboy for each of your two squads and move Nobz with PK to each of your Troop choices.
All of the Boyz will only have Big Shootas so you may as well devide those accordingly and I would suggest two units of 30 each and two units of 20 each in the Boyz units. If you are walking them across the field I would suggest a second HQ with a Big Mek with a KFF smack in the middle of your army. I hope this helps somewhat.