My Nibe 310p broke 1,5v ago. Have been looking for what ever pump I can get a hold on.
Nibe- F370 earliest march/April. F730 in the summer.
IVT 402- April
Thermia Ventec- no answer
Bosch 3800i - Dec/Jan maybe a bit later.
Just asked for the sake about luft/vatten pump. Quantum Etk 6500 -Dec/Jan.
So my bet is that you will have the best chance with Bosch.
That's what all installers and sellers have said to me. (Been in contact with 5 different).
Most of which I have been in contact with refers to the situation as "totally hopeless"
I live in the West coast you might be luckier on your side.
Hope this gives you some answers.