If its an economy thing, you can go to the local hot rod shop and pick up a make-your-own wire kit for a V8 and have enough for 2 sets at around the same price as a specialty made for the specific car single set, and no waiting for shipping.
7mm is the factory OD, but 8mm can be crammed into the cam cover loom.
Avoid Taylor brand like the plague as they crosstalk like mad and can literally confuse the ECU.
Otherwise, Beck/Arnlay sets specific to the car can usually be had at some local parts counters for not a stupid pile of money.
(The B/A wires are blue with metal plug caps BTW & if it matters to your sense of asthetics)
Beyond that, it's pretty much pick an Alfa parts supplier and run with it from there.
And, if you should choose to make your own, there was an excellent article a couple of months ago in Hemmings Sports and Exotic Cars Magazine with pictures showing how easy it is to make your own plug wires. If you cannot pull up the article, let me know and I will send you a copy.
I make mine using 8MM wiring, which will fit through the looms with a loving touch, but the 7MM will work just fine. Tifosi is right on the cost. I can purchase the materials and make two sets for what I would pay to buy a to buy single set already made up.
I get the satisfaction of making it myself and, if one wire should go bad (do not ask how I know that can happen), you can make up just one wire and not have to buy a whole new set just to get a single wire.