I'll answer this without having read through the other comments, so most of it was probably said, but oh well.
i currently have kef R3s in route and nothing else (crappy sound bar notwithstanding).
A big upgrade!
power amp- buckeye NC 252MP (~550)
Yes, amplification is sorted with this.
minidsp-ddrc-24 (~450) + wiim
I would go for the MiniDSP Flex without Dirac instead, it is a proper digital preamp, has better connectivity, all the cables to the back and generally looks better. There are a few different types now, i have the RCA one, there will be one with HDMI soon. I have my TV connected through optical, but HDMI would be nice as well.
I would skip the Dirac license for now, you can add it later if you think you still want it.
To make full use of the Flex or DDRC-24 you also need a measurement microphone, the UMIK1 is used by many.
(or maybe minidsp SHD to cover streaming as well?)
I think you would prefer to replace your streamer every few years when new stuff gets available, and keep the digital preamp.
TT ~500-1000 left over depending on above options.
I prefer the record players from the early 80ies, fully automatic and direct drive. One of the most popular that was sold for a long time, until 1998, was the Denon DP-47F, but the DP-57F or DP-45F are very similar.
Add a new cartridge, for example a VM-AT95ML and a phono preamp that is then connected to the analog input of the MiniDSP. I think the Cambridge Audio Duo or Solo are beyond doubt, maybe you have luck and find one for a good price.
Use hifishark to find used stuff in your area.
PS- this is less important now but would love any insight into the best way to add headphone capability to the above
Well, you buy a headphone amp, like the Topping L30 II and a RCA switch. From the MiniDSP output to the RCA switch, from there to the headphone amp or power amp. You would then use a specific preset on the MiniDSP to EQ your headphones.