Car: 1999 Cavalier RS 2.2

I bought replacement rear struts with the naive assumption that I wouldn't have any problems with them. The installation isn't the issue, it's the fact that the OE boot won't fit the new strut that I bought at the auto-parts store.

So I went to every parts place in town and none of them have boots, they all tell me to go to the dealership. If I buy a boot at a dealership there's no guarantee it will fit my aftermarket strut.

I've been wondering if there's an issue with suspension parts being different for the RS than for other Cavs of my year. When I replaced a strut bearing in the front, the '99 strut bearing had a bottom piece that was too large for the spring that was on my car, they gave me a different year part that fit (don't remember what year). I have all original parts AFAIK.

Any words of wisdom?
Thanks