Check out AMP at
http://www.cobracountry.com/amp/home.html
they make good front suspension replacements for Jags. My front brakes have Disk diameter 310mm,
Disk bolt circle diameter 175mm,
Disk inner diameter 162mm,
Disk thickness 21,08mm(13/16") and use Willwood Superlite calipers with an adapter plate to fit to the original upright.
Check these pictures