Foam speaker surround replacement options

It has been many years since I’ve done this, and in the mean time, many more companies selling kits. My neighbor gave me a nice looking pair of advent “prodigy towers” that I am going to either put in my shop at work or give away or sell once they’re fixed.

Who has the best foam surrounds these days? Are there people making them that don’t rot with age? I did a pair of large advents 15-20 years ago, and the surrounds still look and feel new. Sadly I have no idea who I got those surrounds from!

Any help/advice would be appreciated!
 
You don't give your country of location which may be handy in identifying reputable suppliers.

I think it may be safe to say that today's foam formulations will last longer than yesterday's.

There's probably more UV protection etc. built in.