For a mid-Fi(ish) triple play in the $1K-$1.5K per amp range, here are a few I'd recommend for ZMFs based on what I've tried/own:
Solid state: V222 or V202 (single-ended) which is about $1K less than V281 minus the gain adjustable line outs, and a bit less power than the 281, but still retains the full, warm and smooth characteristic of the V2 series. Superb engineering and quality from the Lake People/Violectric/Nimbus team. Homage is also a solid recommendation pretty close in sound quality
when I did a comparison of the two.
Multi-tap Output Transformer Tube: Icon Audio HP8, base model ~$1.5K. Works very well with the Caldera and dynamics and it has an impressive powerful sonic presence about it. The impedance matching switch works nicely for a range of HP's. I'm loving it with several music genres especially various rock and vintage recordings on the Atrium Open. Solid like a British Mark V tank, well built, nice slim desktop size and the casing does not get uncomfortably hot.
Tube OTL: Decware for dynamics. I tried the versions ZMF set up at the NYC CanJams and thoroughly enjoyed the spacious, holographic experience. I have a CSP3 base model on order with Decware at less than $1.5K. FYI, they have a very long waiting list. Put my order in back in early 2022 and still have a few more months to go but I know it'll be worth the wait. If I'd known earlier about the ZMF/Decware collaboration I may have gone that direction but it was above my price target at the time.
I also ordered an LTA Velo when they had a recent promotional sale and looking forward to it arriving soon. I enjoyed speaking with them at CanJam and they had ZMF HPs at their table for the demos.
Edit: corrected the description of HP8