Your thoughts would be appreciated..

I know of one that works well with the 6.3s. The Monarchy SM-70 combined with the Sols will have you melting in your seat! One is plenty..but two should be absolutely terrific.
You can buy them used for around $375.00 a piece and sell them for what you have in them.Very, very musical little amplifiers! Don't let the 25 wpc fool you..it's enough to rattle windows and shake walls with the Sols.If you can get the SE-160s even better.

Have fun!

I'm wondering if you might be best served to upgrade the lot. I use a Creek 5350SE and find it to be a fantastic amp. If you get a seperate power amp perhaps you could sell the creek and used the funds for a dedicated pre amp and upgrade both.

McCormack DNA 0.5--used should be in your price range. Will sound great & gives a significant upgrade path (through SMCAudio).

Creeks use passive preamplification stage. Therefore it's recommended to find an amp with high input impedance and sensitivity >1V to a full output power.

Great feedback - thanks everyone