Just to clarify the basic requirements
hi steve,
flame resistant overalls, dont need to be msa or fia spec, so the type autograssers and banger racers use is fine.
complete gloves, no open backs or fingerless, dont need to be flame resistant tho.
helmets, have to be msa spec, so helmets with the following stickers on them.
fia 8860-2004
snell sa2010
snell sa2005
snell sa2000
BS 6658 type A/FR
seatbelts, 3 point is fine, so the standard 3 point that comes in your every day car, you can use harnesses they dont have to be in date.
mudflaps behind all 4 wheels, extending 3.8mm either side of the tyre, and maximum of 7.6mm off the ground. they dont have to be the 4mm thick type rallycars use, they can be old rubber floor mats or anything that will work as a mud flap.
extinguisher, a 2L AFFF handheld is fine.
you can use standard seats or replace the drivers seat for a competition seat, the competition seat doesnt need to be msa or fia spec, and doesnt have to be in date.
if your car doesnt have laminated windscreen it can be replaced with polycarbonate, or just put wire mesh over it. my karmann ghia doesnt have a laminted screen, so i got some mesh from B and Q for £3
cheers
Rob