No, no reverse gear is required for the SVA test.

This will change when the new IVA (individual vehicle approval) test comes in to replace the SVA, possibly next year but more likely in 2010/11.

From then all four wheeled vehicles will need a reverse gear, but there might be a weight exemption, 500kgs is being mentioned, so your quad should be exempt.

Get it finished while the SVA is in force, you won't have a problem!

Cheers

Chris