Well, they all do the middleman job between the coil and the spark plug OK. Depending on who you talk to, this is better than that, blah, blah, blah. . . If it's an aesthetic thing, just pic the prettiest one.
I have an MSD 8579 and, for the most part, it's been a good distributor. But I've had problems with the mechanical advance mechanism in it. Right now it's sticking 5 degrees advanced at idle and making the car run like [censored] below 3000rpms. This afternoon I'm locking the advance out and installing an MSD 8980, which will give me an electronic controlled timing advance-a linear 20 degree advance from 1000 to 3000 rpms.
So, once the jump from points to electronic ignition is taken, I think the important question is between using a vaccum or electronic controlled advance.
But there's nothing wrong with the stock ignition. This guy turned an 11.7 with points. . .and 302 tunnel port heads.
I have an MSD Billet, 8598? not sure the part # but it's the one with the steel gear. The biggest improvement it made on mine was the consistency and knowing that all the advance is locked in. The first time you drive with it after you adjust your advance to come in earlier(lightest springs) you'll wonder why you never did it earlier, it's a noticable improvement. I remember in your earlier post, you were wondering how it is adjusted, basically just like a duraspark or aftermarket recurve kit, you can change the internal springs and bushings which will change how fast and how much the mechanical advance comes in. There are two springs and one bushing if I remember right. So you can run like 7 different advance curves based on the 3 spring sets they give you plus like different 3 bushings which control how much mechanical advance in 3 degree increments if I remember correctly. If I had to do it again, and if they came in different color tops, the new Crane digital distributors look AWESOME. They have some ridiculous number of built in advance curves with or without vacuum and its all digitally adjustable so you don't have to take it apart or anything. I went with a Crane ignition box versus a MSD and was very impressed with the quality of their components, which are about the same price as the more expensive msd counterparts. One more thing, you might want to research if your air cleaner assembly or strut tower brace or anything will interfere if you get the larger wide point cap. I've never seen anyone run the wide point cap and a 14" air cleaner dropped past the distributor cap/wires on a SBF windsor. You'd either have to run a small drop or flat air cleaner base limiting element height, or you have to run a smaller diameter air cleaner or custom assembly. If I had to do it again, I'd jsut go with the smaller diameter cap, I don't think it makes a difference.