Hi J.
Have a look at the thread 'does persistence pay off with plastics' it was a couple of weeks ago. Lots of good advice there.
On the Goldie you need 3/8th oz, 1/2 oz, 3/4oz and 1 oz heads for the 24's and 36's and 1.5ozs to 2 ozs for the 50's.
General rule is 'the lighter the better' and if fishing for the macks you dont need to get to the bottom so you can go lighter still.
Remember the sinking speed of a 1oz weight is around .8 to .9m/second and 1/2 oz is about .6 to .7m/second. Assuming no current you can judge what suits you best and how far up mark to start your drifts assuming it will take 60 - 90 seconds to get the SP down to the fish.
IMO:
7inch gulps are very good and suggest you dont go smaller than 5inch.
Mono or braid, 6-8kg with a decent leader (20-30lb). Use wire for the spannos.
Have fun
Plato