My Own Arcade Controls

[BoomTrigga]

I have a few questions that I was hoping someone knowledgeable could answer for me. I'm planning on building an arcade control unit to use with MAME 32 and I was curious of three things
 
1.)  How many buttons are used maximum in each of the 4 modes of games on MAME.  Namely, the maximum number of buttons used in a 1 player, 2 player, 3 player and 4 player game.  
 
2.)  What would you suggest I have in/on this arcade control panel?  Including the number of buttons per joystick (I plan on making it a 4 player panel)
 
3.) What type of joystick and trackball should I have and from where?

I also have a question about the light gun games.  What type of "light gun" can I use to play the shooting games on MAME?  I saw two types on wicothesource.com, but I'm not sure if they will work with a PC based homemade arcade unit.

[Generic Eric]

If I recall,
player 1 & 2: 6 buttons each (typical fighter layout) or 7 buttons each (you may have seen this on some examples, some people like to blend a Neo Geo arc layout into a Capcom layout.
player 3 & 4: 4 buttons each (thats the max used in a game from what I have read)

The best advice you will get on the acutal button placement is to take a piece of card board and use that as a means to test.  that way all you waste is cardboard.

edit
http://www.oscarcontrols.com/joycompare/joyreview1.shtml

[eightbit]

There are only a few games that use more than 4 buttons for p3/4. Most 4 player games use 2 or less. Depends on what you want to play and how important it is to you.