Arcade Primer  
MAME and Monitors
Arcade Monitors
Saturn Mod
Arcade Primer
Finding a Cabinet
IC Pinouts
Here's a very quick overview of JAMMA and arcade cabinets in General.
It's not definitive - by any stretch of the imagination -
but should be enough to get you started.

Some Background Aracde Info
Without going into too much detail, there's basically two types of arcade cabinets. The first type being 'dedicated', these are usually expensive, have special controls and maybe some force feedback mechanism.
Examples are things like Daytona, Virtua Cop, Manx TT etc
The second type are generic cabinets. These usually have 1 joystick and three or six buttons per player.
They can have anything from Tetris to Mortal Kombat in them, the current game in the cabinet is usually only indicated by a card on the front glass and/or the lit 'marquee' at the top of the cabinet.
  These generic cabinets are the ones we're after, specifically JAMMA cabinets.
JAMMA is a standard for arcade game PCBs, it defines a set of input and outputs that appear in a set position on the edge connector of the JAMMA board.
So, in theory, any JAMMA board can be placed in any JAMMA cabinet; there are, however, a couple of exceptions...

Firstly the JAMMA standard only allows for 3 buttons per player, but games such as SF have six buttons.
A 'six button cabinet' will have an extra connector which plugs directly into the board and is seperate from the JAMMA connector.

Secondly, JAMMA does not define the 'orientation' of the monitor.
The monitor could be vertical (i.e. turned on it's side, as in 1943, Tetris etc.) or horizontal (like a normal TV, as in just about all games these days)

The type of cabinet we need for the 'Video Consoles'2JAMMA projects is
a 2 player, Six Button per player , JAMMA cabinet with a 19" Horizontal Monitor.
(you can get a bigger monitor, but 19" is a nice standard/cheap size)

For the PC2JAMMA project I recommend a 2 player Three Button per player Cabinet,
with a monitor that can be rotated to be horizontal or vertical.
You can ,of course, get a 6 button one, or one which only allows the monitor
to be horizontal, or one which only allow the monitor to be vertical
3 buttons just means less soldering, and a horizontal and vertical monitor orientation means
more games.

There is a general shorthand when refering to arcade cabinets something like
Silverline 19" JAMMA 2 player 3 button V/H
- Which means:-
" A Silverline (manufacturer) JAMMA cabinet with a 19 inch monitor, 2 joysticks with 3 buttons per joystick.
The monitor can be placed in either the Vertical or Horizontal position."

Some other useful terms
Upright - standard size upright cabinet

Cocktail - Those old 'pub table' type games, where the monitor was inside the table and you sat down to play the game. These aren't really made anymore and don't have enough room inside them to poke around.

Mini / Midi / Slimline / Cabaret - All these mean a smalller version of a standard size cabinet. These usually have 3 or less buttons on them, as there isn't room for much else.

As regards dimensions, most (if not all) Upright JAMMA cabinets are designed to fit through a standard door.
So as long as you don't get one with a 33" projection screen, you should be okay.