I don't think there is one yet, probably due to the cost. There was incidentally a HN post about an equivalent for midjourney: https://news.ycombinator.com/item?id=34522311

They should crowdsource the training cost

It lends itself very well to a kickstarter type model, where early investors could get repaid in AI use at below market rates on the backend. There's a lot of gaslighting about the difficulty from people who fear hazards, real or imagined, once good custom models start floating around for people to reshape or pare down. A fun one would be training some AIs to make plausible but slightly longer and worse edits, and take sides in editorial disputes with whoever was the weaker side. The time sink, wariness of bots/ensuing accusations, and trend towards massive and uninteresting articles would destroy wikipedia within a year.

I think this is an attempt https://github.com/LAION-AI/Open-Assistant

Alpa is pretty neat. Only 3.0 though. Based on metas. There is a form to fill if you want the full sets.

https://opt.alpa.ai/

This times out almost instantly and never completes any requests

Yeah I tried using the chatbot function, it said the query would take 17 secs but it never actually showed anything.