Really doesn't make a difference who you get them from. I would only recomend that you get ones with a spiral wrapped core.
Also, the outside diameter of the wire is of little importance and the difference in resistance per foot of the quality wires is insignificant as far as function too.
I have been very happy with the Bosch spiro-core wires you get from Autozone. That have a standard size OD (7mm I believe), they are a top quality OEM replacement wire and come with a lifetime warranty. Only down side is no sexy colors (black boots grey wire) if that's your thing.
my .02 is msd or taylor. less resistance=more power to plug. you can also make them fit EXACTLY how you want them to, if you feel up to making your own ends. i tend to disagree on size and resistance not being important. to each their own. a straight, 90*, etc may be necessary with your header/manifold selection.
All of the major companies like taylor, MSD, Moroso, etc. are basically the same. I use Moroso because they have constingency money if you use their wires. I try to support the companies that support my hobby.