Bose 901 Series ii

I would go head and sell those old.. very bad sounding 901's, they are much better speakers out there!..  Used Martin Logan ESL's are much better for the money! Or wait until you can buy some new Martin Logan ESL-X's!

Has anyone ever tried stacking Bose 901s? 

Though almost everyone trashes Bose, I remember listening to my first pair for hours, and they're  some truly great memories.
Bose, to me, has that jukebox bass (warm and rich) that goes surprisingly deep. Nice staging and pleasant voicing. 
Soooo, I'd keep them, buy a nice Integrated as someone suggested. One with a bit of power, because as someone pointed out, they're a bit hungry.
Wyred for sound, makes a good amp.... also consider the LSA Integrated. Used, it's inexpensive and has balls.
Good luck.

PS... be sure to listen to Carley singing 'De Bat Fly in me FACE after buying the new gear.... great fun.

Make that Wyred4Sound.....
oops.

I really think going to a different pair of speakers would make the most sense, the Bose 901's are just so sonically antiquated. I was a young audiophile when they came out, and never did warm up to their sound even back then. Most everyone I knew who had them would always set them up backwards. That is, the  multiple driver side facing toward the listener instead of the rear wall. BUT. If you like their sound, keep them and go after a good high current integrated amp....
Cheers,
Tim