Subaru OEM boots? They’re way better than standard aftermarket. They don’t break in a year. I reboot my Subarus when I get them and never have to do it again even after 100,000 miles. That never happens with aftermarket.
if you’re using 90s axles upgrade to 00-04 Outback style axles. the boot material is better, particularly the outer boot, it’s “stiffer” and the outer boot has more convolutions. They have the tone ring on them, just tap it off with a hammer it just sits on the ridge. They can even be left on but I remove them. They’re a direct swap into 90s EJ vehicles.
I’ve seen silicon boots for sale but I forget where. Google should find some.