AN sizes are really quite simple, the dash number, ie -4, -6, -8 etc refers to the hose size in sixteenths of an inch.... A -8 hose is 8/16", or 1/2". A -4 is 4/16", or 1/4". When you buy the components, it's best to keep them all the same brand and the same product line to ensure compatibility....

Not hard to make up your own, do some studying on the various manufacturer's sites and there are some very good instructions....