I run exclusively on Ampex 499, both 2" and 1/4". I have never had any problem with it in regards to SSS. And if you do a little reading around the forum you will see that 499 has not been identified as having those issues.
I started stockpiling it a couple years ago and now have more than a lifetimes supply. Two years ago it was very affordable in NOS. The hard part for me was/is finding it on 14" reels, which is what I prefer for projects.
*edit: the problem with ebay tapes are many: is it really what it says it is wound onto a reel? splices=worthless in my opinion.
i got a majority of mine from studios up in the LA area dumping all the tape they had. In the mix i acquired some truly awesome masters by very big names. Due to IP laws I cant do anything with them but enjoy them personally. I have fun once in a while remixing some big bands biggest selling albums.