you will need:
- A computer. 1 Gig of Ram is OK, but 2 is ideal. you'll need a pretty decent graphics card with dual monitor capabilities and a pretty decent processor - a fast dual core is better than a not as fast quad core, as the software only uses 2 cores anyway. Most people say Windows XP is best.
- the software: Visual Pinball is the emulation software, and the front end that dresses it up and makes it playable on the cabinet is hyperpin.
- A monitor for your playfield - I wanted to keep costs down, so I went with a smaller option - a 24" Asus monitor. If you want to replicate the size of a real pinball machine, a 37" LCD TV is your best bet.
- A monitor for the backglass - I went with a 19".
- timber - I used 19mm MDF.
- A keyboard encoder. the i-pac is your best bet, available here in Australia, and here in the USA.
- arcade buttons and wire. I used 6 buttons, each coming with it's own microswitch. wiring kits save a lot of hassle crimping connectors on wires. they're available at the above links.
these are the key components, but there are plenty of smaller things I use along the way.