What do I do with this system?

You are right about technology!  Considering that fact you may want to focus on a new disc spinner. It is amazing how far CD/SACD reproduction has come. 

The improvement from Monster will be immense. The other stuff, presumably you liked it then and will like it now. But connected with Monster is like one baby step up from patch cords and lamp cord. 

Wanting to add a turntable, so a tube integrated with phono stage would be good. Except the B&W are only 87dB, would be nice to find something newer/better and more like 95dB. 

Guess my vote is sell it all and start over. Except keep the CD. CD is CD, not worth anything, not worth spending more on either. So just keep it and concentrate on what does sound good, and find a nice turntable.

Agree with Millercarbon on the Monster stuff.  Deposit the Monster in the circular file as quickly as possible.  You might want to read the thread on DIY Duelund helix cables.  You could make your own really nice cables fairly cheaply, then plug them into your system and see what you really have.   Get some decent cables and give yourself a month to listen while the cables burn in. I'm not a fan of B&W or Bryston, but you aren't trying to please me.   If you see yourself focusing on digital, or if you have a large collection of CDs, you might want to start with replacing the source.  The Philips is beyond long in the tooth.  You can do a lot better.   Might want to think about a good server like an Innuos that will allow you to burn your CDs and an Orchid DAC.  You would have a pretty decent front end to build around. Or, If you want to go vinyl (or even if you don't), you should think about getting a Lyngdorf 2170 which has a very good internal DAC and an internal MM phono preamp.   You could run coax out from your Philips to the Lyngdorf and probably be in pretty decent shape.   The Lyngdorf will be capable of driving a fair number of good speakers.  You can usually pick up a 2170 used for around $2500.  It is an outstanding piece for that kind of money--MM phono, excellent DAC, and Room Perfect digital room correction.   It would be hard to do better for that kind of money if you find yourself in the start over mode.   I use a Lyngdorf in my second system and love it.