Sparco 3 point harnesses, only 2" but they are FIA approved, road legal and made by sabelt, as someone has already said. Never had any problems with them!
I've got 2" Sabelt 4 point harnesses, didn't set out to get them but they were very cheap on ebay. Haven't had any problems and have been using them for about a year now daily.
is there an advantage to using 4 point ones rather than 3 for casual track use? also would something like this be ok? i.e road legal and up to the job http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=SAB901020N cheers
4 point is better but does depend on what mountings you use. Ideally, you don`t use the same as those of the standard inertia reel system however many locations there are. I didn`t think any harness ... bar a certain Scroth item were completely road legal but mine have always passed the MOT. Going on track is not a casual exercise, prepare as best as possible even if it means waiting a while longer.
My dub runs 2" 4 point lukes, mounted in standard points at the front, and wrapped around the rear strut brace. Pug uses Sabelt 3" 6 point, aircraft buckles and eylet mountings. Road legal harnesses (and FIA for that matter) will have a tag showing they are road legal. I'd recommend at least 5pt to prevent submarining in a high speed sccident.