Old Man in a Jag

Hi, I have just joined the Jaguars Forum and wanted to know if anyone has had any work done on their XFR by Spires. I am considering having an engine remap, exhaust, brakes and possible coil overs done. I would appreciate any information anyone can give me before I go ahead and have this work carried out. Or if anyone knows of another company, I would be most grateful. Cheers