For 4-way sticks you've got:
Original Ms. Pac stick (leaf switch, shorter throw, non-standard cp mounting, no longer manufactured)
Wico 4-way ..
not 4/8 way (leaf switch, longer throw, standard mounting, no longer manufactured)
Ms. Pac / Galaga reunion (micro switch, longer throw, standard mounting, currently sold by Happs)
Ms. Pac replacement (micro switch, shorter throw, non-standard cp mounting, currently sold by Happs)
Which is better? It depends on what you need.
First, you have to decide if you want the short throw or the long throw, and if you want short, is it worth the extra work mounting the thing?
Second, have to decide if you mind clicking. If you don't, then the micro-switch sticks are an option, and they're sure easier to get, since you can just hit
http://www.happcontrols.com and order 'em up.
If you want non-clicking leaf switches, which are what you found in almost all 4-way games back when they still made 4-way games, then you've gotta work harder to get 'em. (possible sources: ebay, BYOAC buy/sell/trade forum, various net vendors, pulls from scrapped cabinets, local operators) They're not really that tough to find if it's what you want.
Personally, I won't use microswitch sticks. I'm too much of an old fuddy-duddy to convert (unless I'm playing old Nintendo titles. I did pick up some Vs. cab sticks for those

) As for the stick throw, I don't seem to care. Back in the day, I played on both types so much that they both feel natural to me, so it just doesn't matter.
Just a quick bit about 8-way sticks- you've got the same considerations listed above, but then add in Optical Switched sticks (Haps Perfect 360), Mechanical Rotary (Ikari), Optical Rotary (Blitz), Right/Left Rotary (Xybots)... and the list goes on; there are lots of types of 8-way sticks. Do you want ball or bat handles? Do you want a trigger? A thumb button on top? Do you want these extra functions? And do you wan't 'em in you primary sticks, or as separate options? Figure out which features you want and then you can narrow down your list.
Good luck!