Get a video board capable of at least 640 x 480 x 16.7 million colors. Today's video boards far exceed this, but a 486 computer may not. Put a significant amount of money into your TV monitor. It will outsurvive several computers. You can't see the cheaper dualscan LCDs in daylight.
Sunlight washes out both.
Put a sunshade on the passengerside window. The sound card provides the critical interface between the rig and the computer. The SoundBlaster line by Creative is the industry standard and you have a better chance if you stay with the standard unit because the software will be tested using the industry standard hardware. If you want to download software, you will need a modem and an Internet connection. Don't waste your money on anything less than a 56KB v.90 modem.