Hi, thanks for the replies, trying to keep costs down as also have a shock absorber to buy, welding few holes to cover, and on edge of needing 4 new tyres aswell.
I've tried TCB, used many times successfully, but no luck on this item.
I've found this sound like right sort of thickness: £234 https://ultraracingshop.com/products/ultra-racing-rear-anti-roll-bar-ar23-209?rq=mk_toyota~md_supra-jza80~bg_all-models~yr_1994
I will try and see if whifbitz sell just the rear kit as on the website it has front and rear.
Ebay has TRD kits but all in USA so lots of shipping and taxes on top.