OP- once you have fit dialed in, so saddle height is good, stem length and angle are good, etc- take that to a ship and ask them to cut the cables to proper lengths. Good lord there is a ton of excess cable in that picture. That stuff can easily get in the way if it's flopping around with excess length.
But I'd you do it after you have the fit set, you won't end up with it possibly too short.