Hi Mate,
In terms of which colour foam to use, it's all down to preference but my rule of thumb is if your fishing in the upper half of the water, then i use black foam and if your fishing in the lower half, then use a brighter colour.
My thinking behind this is that when the carp are looking up, black will stand out against the bright sky, when they look down, a bright colour like yellow will stand out against the dark bed of the lake. This isn't a stead fast rule however, as any colour will work in any situation but its just a rough guide to work from.
The easiest way to net the fish with a long hooklink is to drop the lead, which will allow you to wind in further, or use a zig float.
If i am fishing with a zig float, then i use the lead set up the float packaging suggests but if i am using "fixed zigs" then i always use a lead clip with heavy leads. That way i can make sure if i am fishing super long hook links, then i can put the pin in the lead clip and fish drop off style or take the pin out if i dont need to drop the lead.
I would also always use a ball swivel as it gives max movement and prevent line twists. Fox do a great little kit's which comes with everything you need to fish zigs, i will post a link below.
Fixed Zigs
https://www.anglingdirect.co.uk/fox-edges-zig-lead-clip-kit
Adjustable Zigs
https://www.amazon.co.uk/Fox-Edges-Zig-Float-cac753/dp/B07T5RJB7D
Also they have a couple great short videos on their youtube page which demonstrates both types of zig fishing, which i found really useful, if you just search for fox zig fishing, you should find them
Sorry for some of the grammar, i wrote this in a rush just before a online work meeting :')