Amp/Pre-amp recommeded for Soliloquy 6.3

Sugden Masterclass integrated. I use a Sugden a21ap with my Soliloquy 5.3i and its a wonderful combination.

Although I understand your desire for solid state control over the lower frequencies, this can be convincingly and musically achieved with certain tube amps, the lowest cost of which is the Aronov LS960, or even the LS960I integrated which I use in one of my systems.
For a system not requiring built-in phono, the LS960I succeeds in providing the most satisfying sound of any reasonably priced integrated choice, saving you money that is then available for buying a great power cord and upgrade support such as cones or footers of your own preference.
With such fine stock performance it is not necessary to tube roll although that is the blessing/curse of tube component ownership.
In a 20x30 listening room with its nine foot ceiling there is even enough power to immerse myself in either Mahler's "Resurrection" Symphony, or a jazz drum with percussion extravaganza (formerly, referred to as music to break a lease by).