Conventional wisdom would point you to the Lector amp. I don't think a 24 wpc tube amp would be able to do the woofers on the S5.4's justice. I've always been intrigued to try a tube amp with my Dyn's but am too content with my current solid state amp to gamble.
Keep me posted if the Canary tube amp ends up working out for you with S5.4's.
Keep me posted if the Canary tube amp ends up working out for you with S5.4's.