Tuckers, C. percivalliana is well known for its vigor!
If you canget an alba or semi-alba, go for it! They are fantastic! IMO the best alba and S/A Cattleyas, regarding labellum's color and contrast! Normally also a pretty goog shape, even though a bit smaller for standard AOS parameters (which IMO have forgotten that species behave different than MEGA Monster Hybrids!) There is also albescens like 'Caracas' which are also very very nice!
Unfortunatelly, as you said, they are not offered very often..
I am looking for alba and S/A percivalliana since quite long and without much succes.. (next year I will get an alba coming from Brazil)