sorry for the inconveience(but sometime i can not find the chinese input, and too slow for me now).
My point is: LS3/5a is good for ur second system(or in ur bed room), but not good enough for ur main system. U can try it, as i siad, even u will sell it, u will not lose money.
And for lS3/5a, no need big power amp, 2A3(2W) or 300B(8W) also enough for it, and Marantz 63 also enough for it.