Decent amp to match Raidho (Eben) X-Streame speakers

Hi all:

I'm a newbie here.  I purchased some used Eben X-Streame (Eben was purchased by Raidho as I understand it)  bookshelf speakers a few years ago from a friend and absolutely love them.  However, we have a big living room and I think my current amp is underpowered for them.  It's hard getting info on the Ebens, but I think they are rated at 6 ohms.  My current amp is a Marantz PM15S1, rated at 90 W at 8 ohms.  Like I said, it struggles to drive the speakers at higher volumes.

Does anyone have any suggestions on 1.  minimum wattage I should be looking at for these speakers.  2.  well-matched amps for those speakers that I could pick up used in the $2500 - $3,000 range?

I saw a Devialet Expert 120 advertised here that sounds like it could be great, but I'm worried that it's not powerful enough.  Sigh.

Any help much appreciated!

Mmmmisha