Wait until they new
NG regiments are released and order the netter bits from
Battlewagon Bits.
Otherwise, I'd suggest getting some fine netting, like from old stockings or a minnow net, roll it up and put it in the gobbos hands as if they were carrying it (or drape it over their shoulders?). K&S also has etched brass sheets so you could possibly model some gobbos ready to throw the net, though you'll eithen need to or want to sculpt an edge to the net and some weights. Regardless, you're in for some work if you convert it.
My last suggestion would be to find some
v5 or earlier gobbos with nets. It was the v6 figures that were oversized, the older figs don't have the same scale problem.