If you really follow the speed limit signs - especially those suggested for curves get the T/A's. If you enjoy spirited drives get the Avons or Yokohamas or Hankooks or etc. I started with T/A's and found myself tip toeing around the track until I switched to Hoosiers (not a street tire ).
I had this part btreak several years back. My research found that it is a Lotus part. It was available thru SJ Sports cars in the UK. I bought mine from Bean Engineering here in California. The part number I have is A082F6231F - Good Luck in your search.
Best thing I ever did was add electric Chrysler Cross fire mirrors to the lower corner of the side windows. The rear and side vision was so improved I did not get nervous when driving in traffic for fear that I would miss seeing the surrounding traffic.
Best addition ever was the installation of electric mirrors from a Chrysler Cross Fire. I installed them on the front lower corner of the window and good set them to have great rear and side vision viewing. I have since sold the car so can't show you pictures.