Next - Tube Preamp, Integrated, and/or Crossover?

I am looking for advice on the next step(s) I should take in improving my system. I tend to listen to female vocals and simpler music but also full range rock more occasionally. I know my current system is on the lower end except for the mid-level CD player with Amperex white label PQ tubes which has made the system sound a lot better. 22' x 28' room with system on long side.

Current system:
Raysonic 128 CD Player
Rotel 1068 Processor (used as preamp)
Rotel RB-1092 (500W Class D Amp)
Paradigm Studio 100 V2 with HF capacitors and resisters replaced. LF unchanged. Bi-Wired with Zu Wax cables.
Zu Varial interconnects.
Zu Mother power cords.

Option One changes:
HF - Cary SLI 80 Integrated straight to speakers
LF - Preout to NHT Volume Attenuator to Rotel RB-1092

Option Two changes:
Cary SLP98L Preamp
HF - Cary 300SE Mono Tube Amps
LF - NHT Volume Attenuator to Rotel RB-1092

Option Three changes:
Cary SLP98L Preamp to Marchand 2-way Crossover at 250hz to
match speakers LF crossover.
HF - Cary 300SE Mono Tube Amps
LF - Rotel RB-1092

Main questions:
1. Can mixing 300B tube amp for HF and solid state amp for LF work well if volume levels can be matched?
2. Is difference between integrated and having preamp in system worth it given this level of equipmet?
3. Will using the Marchand crossover to separate the LF and HF before the amps make enough difference to justify cost? Would a cheaper one like Rane or Ashly do?
4. Is it better to take the extra money for all the extra equipment and spent it on one more expensive integrated amp.

Thank you for the advice.
First try the 300SE full range if you can. See if the volume is acceptable as split freq bi-amp will only get you a slight bit more volume with the 300SE.

I'm not sure on your possibel paths, but definately get a buffer before the NHT volume to keep the input impedance high for the 300SE amps. Otherwise you wil get high freq rolloff and will sound crappy. Buffer is not that much $$ some even have volume controls built in (Dodd). Splitting signals is a tricky thing unless you know all the specs and they mate well. This has happened to me, that's how I found out. You want to preserve the mid/HF as best as you can.

Actually I like #4 as your best choice. It's hard to get all that stuff to work just right, and more that likely it will be wrong. Going tube or SS is your choice, but some new integrateds are just fantastic. Simplify your search and auditioning and you will be very happy. Good luck and have fun.
My intent was to only attenuate the volume of the LF and not interfere with the 300SE. I definately may be erring toward the option 4 direction. Thank for the help.