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Warboss Black Claw Iron Jaw - Iron Gob, 'Eavy Armour - 100
Nobby McNob - Power Claw, Slugga, 'Eavy Armour, Waaagh Banner - 79
Big Trev - Choppa Slugga, 'Eavy Armour - 31
Nobba - Choppa Slugga, 'Eavy Armour - 31
Chuck Nobbis - Choppa Slugga, 'Eavy Armour - 31
Trekboy - Shield Generator, Choppa Slugga, 'Eavy Armour - 40
Skar Boyz - Full 20 man units - Nob w/ Tank Bustabomz, Iron Gob - 3 Burnas - 256
x2 Kommando Units - Full 10 man units - Tank Bustabomz, Iron Gob - 294
x3 Slugga Boyz Units - Full 30 man units - Nob w/ Tank Busta Bombs, Iron Gob - 3 Burnas - 924
x3 Gretchin - 20 Gretchin + 1 Slaver unit - 216
Total - 2002 Points
Pretty much infiltrate with the Kommandos to draw fire and if they can get close to the enemy tanks, have a go at blowing them up. The gretchin will pretty much stretch across the table providing plenty of cover and blocking the advance of any enemy CC units. Each Nob in my regular units is ready to slap a tankbusta bomb on the side of any advancing Dreadnoughts, hopefully giving the same outcome as the Dawn of War introduction lol.
Any help and suggestions would be greatly appreciated.
I'll admit I use a Chosen Aspiring Champions unit in my Chaos army, but that's because they fill the role of Terminators (and have more power weapon attacks for the points) without me having to get them something bigger than a Rhino to ride in. A Nob squad does not strike me as the best use of points - you're paying extra for a small, expensive elite squad when Orks are all about large hordes. The only real use in your current setup for them is the kustom force field, and you get enough cover from your 3 full unit caps of Gretchin.
You've hideously overestimated the cost of your Warboss - a Warboss with just Iron Gob and 'Eavy Armour would only be 74 points, not 100. And if you're paying for a power claw and 'eavy armour, go the whole hog and give him Mega Armour - a 2+ save is always nice, and even if the Boss does move slowly as a result, he won't need the Mek's support.
Get the power claw and Waaagh! Banner off Nobby McNob, and put the Nobz in Mega Armour too. After all, a unit of power claws won't be needing a Waaagh! Banner much, and by the size of your other mobs you won't need to reroll for anything but your Nob squad.
Let's face it, in the current edition, Kommandos are not good. In any way. They can't charge at an enemy more than 18" away in a single turn like Trukk Boyz, they can't boast real numbers like Slugga Boyz or even Skarboyz, they can't boast the special weapons capacity of Burna Boyz or Tankbustaz, and they lack even the pithy 6+ save that could conceivably save the Nob from IG bugzapper fire. If you're at 2000 points and you know what you're doing, your opponent will too and probably won't be fooled by the Kommandos. Take them out, thereby saving points for scarier things, like, I dunno, another Skarboyz unit.
Gretchin are good mobile cover, but mobs of Killa Kans are better mobile cover. A Kan, being a Vehicle, is a Large target, and therefore your opponent's units will NEVER be able to shoot your Slugga Boyz until your Kans are down. And with AV 11, that means they lose at least one decent Shooting round completely, as opposed to saving your Boyz on a 5+. Then again you're best off using both from what I hear.
You might want to consider using the Clans rules and playing Goffs. They can take Skarboyz as Troops (in fact, they HAVE to take at least 2 Skarboyz units as Troops).
Tankbusta Bombz are not to be relied on if only the Nob has them. You're better off with a power claw - Initiative 3 doesn't lose much from it, and you can always use your normal close combat weapon (slugga) when charging if you need the I 6 attacks. Besides, you have enough AT capability by filling up your heavy weapons cap with Burnas - they roll 2D6 Armour Penetration against all vehicles and get a full complement of attacks rather than 1 attack.
Oh, and you went over the limit. There's no shame in being a few points below your limit as far as I know.
On the plus side, you HAVE maxed out Burnas, and they are THE most versatile weapon in all of Warhammer 40,000. Period. Carry a bunch of them at short range and you're ready for anything. Also, as I said, huge Gretchin units make good cover, and unlike Kans they can tie up small, scary units like Terminators or my Chosen Aspiring Champions - "Oh, wow, your ultra elite forces killed 42 points worth of troops in a whole Assault phase!" - while your Boyz and your super elite forces (Skarboyz, Warboss & Nobz) take out the meat of their army.
Overall, there's quite some room for improvement, but it's a competitive enough army and I can tell you now I would be absolutely TERRIFIED to see that many models against my 2000-point Chaos Space Marines army even if they do only have a 6+ save. MEQs can only spew out so many shots., and MEQ close combat troops WILL die horribly if the Orks get the charge.