Derby Magic

They offer several models of IR timing systems.  Timing is out to 0.0001 seconds.  Compatible with their own race management software and GrandPrix Race Manager, using the Custom Timer interface.

Fast Track Timers by Micro Wizard

They carry several different models of IR timing systems with a resolution out to 0.0001 seconds.  They do offer their timers in kit form, so you can save some money by doing some simple assembly.  Compatible with GrandPrix Race Manager and some other race management software.

They also offer a combination light tree and solenoid start gate unit.

NewBold Timers

Manufacturers of Turbo, Turbo Lite and DerbyStick timers. All of the NewBold timers are easily expandable as your needs grow and have a precision of 0.0001 seconds. Their Turbo model has large numeric displays above each lane to indicate finish order. Their Turbo Lite and DerbyStick timers use an incandescent light source (you provide) and regular photo sensors for finish line detection.  Results for Turbo Lite are displayed on a handheld unit or via optional computer display.  DerbyStick must be used with a computer, but you have to hope that you don't have computer problems.  You can use Turbo Lite and DerbyStick timers for other types of races like Space Derby and Raingutter Regatta. Compatible with GrandPrix Race Manager and some other race management software.

SmartLine Timers by eTekGadget

Timers for 1 to 8 lane tracks.  Reports times out to 0.0001 seconds. They also carry a USB video capture device which snaps a photo finish picture at the instant the first car crosses the finish line. Compatible with GrandPrix Race Manager and some other race management software.

SuperTimer

Uses a mechanical sensor flag that is hit by the car as it crosses the finish line. They claim this sensor can withstand millions of hits without damage. However, from the pictures on their site the sensors can get slightly bent, so all of the sensor flags may not line up well, meaning that the lanes with the flags bent less actually have a slight advantage. Finish results and times are announced audibly, though they also support a computer interface. Timer precision is claimed to be better than 0.0001 seconds.  Only their rather expensive software will work with their timer. Though, some people have successfully used this timer with GrandPrix Race Manager, using the Custom Timer interface.

Swanberg Technologies

A very simple modular IR system where you build the housing for the electronics and then wire the units together. There is no computer interface available and timing precision is only 0.001 seconds.

The Champ Timers by BestTrack

Offers timers manufactured by eTekGadget especially for BestTrack. Timers for 1 to 8 lane tracks.  Reports times out to 0.0001 seconds. Compatible with GrandPrix Race Manager and some other race management software.

The Judge Timers by New Directions

Manufacturers of The Judge and Transponder timers. An IR timing system that comes with a stopwatch or computer interface options that allow display of times out to 0.0001 seconds, though they make no claims as to precision on their site. They offer used or older models at reduced cost, or you can rent a unit. They also offer a version that works in sunlight. Compatible with GrandPrix Race Manager and some other race management software.

They also offer solenoid start gates to fit most tracks and a light tree.