For prebuilt, definitely an Iris keyboard without including switches and omitting the middle plate. If you're fine going smaller then I recommend a prebuilt piantor which is similar to a corne but has a more aggressive pinky stagger. I very much recommend the Iris however since it's the sleekest and well designed for its price with integrated rp2040 MCU making it feel "premium" compared to others in its pricerange with the pcb and mcu exposed in some manner.

Spacebars are normally mapped to one or both thumb keys on either board,

I like the design but yea the price is insanely high for this keyboard.

I also landed on the Iris rev 7, and it being my first I went with getting it prebuilt plus not having a soldering setup. Also, one decision was comparing the shape and size of keyboards using splitkb compare site. The Ergodox EZ and Moonlander were way too spread out for my hands to deal with so I chose Iris. Ended up cheaper than either with no included switches and now I'm practicing how to use only three rows and layers since it's way more comfortable to not move your hands from the home row.

That isn't to say I am not regretting it. The oryx software that ZSA has looks amazingly powerful out the box. VIA is annoyingly limited in how it utilizes its Any key so advanced configuration is also limited. Vial, while having more features, would require reflashing due to some tap_dance_count error which is annoying. If I had more time I would just use QMK but it's way faster prototyping visually and adjusting to how you end up using the keys daily.

Well, you can also get a corne choc PCB kit for around the same price if you take into account the parts to assemble. Add the cost of the additional parts to make the whole board and it still in the hundreds for either kit. A cheap alternative kit which is similar is a piantor by beekeeb.

I don't think it does since it just states it comes with just the boards and links the wiki to get the parts.

If it does then I've got a whole bunch of extras coming my way which I guess I could use for a Corne build in the future if so ._.