I am going to get a set of tires for the classic this summer. Sooner than later as they are old and need to be replaced. I am going with either Cooper Cobra Radial G/T or BF Goodrich Radial T/A. I can get them either at Discount Tire or Belle Tire. Pricing for the tire itself are the same at each location. BFG is slightly more than Cooper. Hagerty Driver's club offers $100 rebate on a set of 4 BFG.

Here's where I would like opinions:
Belle Tire offers 10% Veteran discount while Discount Tire offers 5% for using their credit card (6 months 0 interest) and 5% for Veteran discount. Which place do you prefer and why?
I have not had a blowout or even hit a nail with the tires on it now. Should I get the warranty certificates (or what ever each place calls them)?
Spare is 16 or so years old, but only on the ground for about 100 miles and never seen sunlight other than that. Should I get a new spare as well? If I get a new tire for the spare, probably pass on that warranty certificate.
Would you go with BFG or Cooper and why?
Cooper has a mileage warranty, where BFG does not, but I don't put on a ton of miles with it anyway.

I appreciate all feedback.