when i used 45s i used the yokohama AVS sports. these were a wet weather race tyre for a porsche championship. worked very well in the dry, and amazing in the wet!! im not sure if they still make them though???
soem of the good year eagle F1s and toyo range are in the 45 profile
i believe the avon CR500s are available in a 45? but VERY pricey.
as mentioned - there is LOTS of choice in the 50 profile range, A-048Rs, toyo R888s etc.
- colin.