Ok so it's looking like this so far;

2x30 Orc Boyz w command (soon to be 3x30)
20 Arrer Boyz (give or take, I have a bunch of the 6th edition sprues I got from eBay and I am repositioning arms etc. to make them look good, some are going to be arrer boyz and some dual HW boyz)
30 night goblins
Night Goblin Shaman
Night Goblin Boss
3 fanatics
5 Boar Boyz
1 Warboss

These are the models I have so far, but I also have a box of unbuilt regular Goblins. I am thinking HW+S as opposed to bows. Am I right? I think they will be more effective (I have 10 strays I got from a job lot on eBay as well so it will be a mob of 30) as harrassment as opposed to short bow sissies. Thoughts?

Build them with hw and shield, but put the bows on their backs. Then you can use them either way. :)

That's what we do in the CCUP2, anyway.

Depend what you're going to do with them, If you want them to kill more use spears, if you want then to hold units until you can flank charge with Boar boyz then HW+S would help since I think they get a parry save and if you just want them to support your other units bows could be handy.
Personally I would either run Spears + shields or HW+S, only because I orientate towards combat rather than shooting.

In most of my games I field a unit of common gobbos, they are a bit more reliable then the night gobbo ones and my opponent underestimate them.

I field them most of the time in this set up : 50models, shield, short bows, fc 3 nasty skulkers. And the are pretty awesome especially when they have gift of the spider god on them. Sometimes I field a second unit of 50 with no bows.

Cheers,
G

+1 On the Shields with Bows, they are great in a flank with the Little Waaagh! Sig spell. Even 30 will take apart some good units with proper play. (I hit a Storm vermin unit 25 strong in the flank with 25 Gobbos with shields, broke and ran them down in 1 turn)