I conducted a simple poll on the-waaagh forums to see how the majority of ork players equip the Nobs that accompany their boys squads into battle. 61% had said that they always equip them with a power klaw, and a slugga. However the discussion brought up a possibilty that I had not thought of before.
Is it possible to give an ork Nob a big shoota? Answer: no However, it is possible for an ork boy who has a big shoota to become a Nob with a power klaw. Schematics - the upgrade order is what is important here.
I quote a post from the forums.
Q. If a Boyz mob exchange sluggas and choppas with shootas, can a Nob take a power klaw or a big choppa?
A. You may upgrade the Nob to have a big choppa or power klaw before you choose to upgrade the mob to have shootas, in which case the Nob is not affected by the mob's weapon swap (as he no longer has a choppa to swap), does not receive a shoota and keeps his slugga and power klaw/big choppa instead. He is a lot happier that way!"
24th Feb 2010 http://www.games-workshop.com/MEDIA_Custom...Q_Orks_2010.pdf
However you can give a Nob a PK and Big Shoota as he does not need to swap a choopa for one of these! The upgrade path is: A boy upgrades his sluga for a Big shoota, so has big shoota and choppa, the entire unit swaps its choppas and slugas for shootas, this boy can not do this as he dos not have a sluga, so keeps the big shoota. One boy may be upgraded to a Nob, this can be any boy chose the big shoota armed boy, swap his choppa for a Power Klaw.
On a side note GW does produce a Nob armed with a big shoota and a PK
This in my opinion is they way forward, as you don't lose fire power in the unit for taking a PK, and gets round this stupid FAQ decision.
So next time I go to waaagh, I may have to try that combo out. what's better than a single shot (or in the case of orks...no shot -because if you are close enough to use a slugga, you are typically close enough to charge, or get into close combat.) at 12" range? How about 3 shots at 36" range...and then hit them with a PK. Besides that, it means that at least one of your Big Shootas stays around a bit longer because of the additional wound the Nob has.