Amp and Pre-Amp suggestions needed

If you like the sound with the Vincent separates why not keep it simple and just go with that since it’s a known factor and Vincent makes good and reasonably-priced gear?

Past that, it’s really hard to make recommendations when most of us have never heard (or even know about) your speakers or what kind sound characteristics you like or that are most important to you.  If you could at least share the latter it’d be super helpful in making more informed and meaningful recommendations. 

I'm in agreement with kijanki4 with respect to tone controls. The better your gear, the less you need them.

For a preamp, I would recommend Don Sach's linestage:
http://dsachsconsulting.com/custom%20line%20stage.html

Don builds these by hand and will tweak it to match your amps. The downside is that this means you'll have a 6 - 8 week wait.

I have one and I'd have to spend some serious money to best it.

For an amp, I would suggest looking at a pro amp (e.g., Yamaha, Crown, Crest, Soundcraftsmen, etc.).  

My previous speakers (Martin Logan Spires) loved power so I ran them with a pair of Soundcraftsmen PM860 monoblocks from the 70's. They pushed 900W at 4Ω. Total harmonic distortion was under 0.05%. They were completely silent when no music was playing. If you require big power, pro amps are your best bang for the buck option.

" I'm in agreement with kijanki4 with respect to tone controls. The better your gear, the less you need them."   Thats false.  At 67, my hearing is going and tone controls can be a blessing.

Mcintosh 

i agree with stereo5 in his statement about tone controls

many many times listening to music i wish i had tone controls handy... if for no other reason than different recordings can have widely varying tonal variations (esp. too hot treble)