I'd use a 25mm if you can find one. If not your standard one will be fine, all you need to do is run a pipe from each outlet of the master cylinder to the 2 t pieces on the chassis rails, throw the modulators in the bin/on eBay job done

As said you will need a non ABS reservoir aswell (no return lines if theres no ABS) and obviously to bleed it before someone starts picking holes lol