Right now, I'm not interested in the Chinese vs non-Chinese debate. I think that unless a magnificent, miraculous used piano in the $4000 range appears, these are our choices.
I'm not interested in the Chinese vs non-Chinese debate either, so that makes two of us.
Anyway, in your case the choice is between two Chinese pianos.
Steigerman pianos usually offer upgrades to basic Hailun models. If the Steigerman model is indeed the 123, it probably has cosmetic upgrades (a slow-close fallboard and a brass kickplate over the pedals).
It MIGHT also have performance upgrades such as different hammers or a different action. BTW, the Steigerman 123 is 49" tall.
The Hailun H-1 is a new basic Hailun model. It probably has a more recent date of manufacture than the Steigerman. It probably does not have the mentioned upgrades. This may or may not be important to you. If both pianos are 'new' and set up well to perform musically, the cosmetics would not make any difference to me.
Steigerman Music has imported many pianos from many different manufacturers over the years. If and when their relationship with Hailun ends, they may source from another Chinese maker. On the other hand, in the present slow sales climate, they might simply quit importing pianos. I have no specific reason to think that, but it is a possibility. The Hailun name on the Hailun piano is probably a safer bet to continue as an ongoing enterprise, but in the present economic climate for piano retail, even that is no sure thing.
Warranty service on either piano would probably be handled by Hailun. so I don't see warranty as a basis for choosing the one over the other.
If I were in your shoes, I would opt for the Steigerman if the price could be brought down lower than the Hailun. Many dealers are closing out the Steigerman premium line, so you may have the leverage to do that.
Both of these are much-better-than-average Chinese pianos.