Great info! Your phono stage has the gain and impedance (loading) flexibility to handle just about any cartridge. No significant restrictions there.
It's great to see a fan of new music who prefers honest, uncolored components. Most classical and jazz listeners understand this, but some who listen to a lot of amplified music do not.
CARTRIDGES
- choose a LOMC (you've got the phono stage, might as well make use of it)
- forget Grado (very warm, as you presumably know)
- forget Koetsu (warm)
- maybe forget Benz (warmish, mids are very present but bass is a bit round/soft)
- choose a cartridge with a fine-line or micro-ridge stylus (these trace HF's better than elliptical and especially conical styli, cleaner sibilants, tighter consonants, cymbals sound like cymbals instead of white noise)
- choose a mid-compliance cartridge (12-18cu, this will open the door to a wider array of tonearms
- buy new (unless you're a risk-taker)
- brands to consider:
Dynavector (haven't heard, reputation for fullish mids)
Lyra (clear and clean, but a bit cool/lean at this price level)
ZYX (very clear, clean, neutral, natural, wonderful upper mid-HF's, bass is clean and tight though maybe a touch lightweight at this price level)
I'm sure there are others...
TONEARMS
- choose an arm of medium effective mass (11-15g, this will mate well with a broad array of mid-compliance carts
- buy used (unless you want to raise your budget)
- brands to consider:
Rega (higher models)
SME (double check mount for compatibility with SOTA)
Origin Live
Morch (if you see a used DP-6, buy it)
Lots of others...
Sample solution:
RB900 listed now in classifieds $575
ZYX R100 Yatra from SoraSound $1140
Many others are possible.
Good luck!