No, I think Mejzlik props are discontinued, we have 2 new props, the first is almost identical to that Mejzlik, but it has improved airfoil, and it has lower pitch. It all together makes that prop run at higher rpm at aproximately the same consumption and little better RE number, makes higher static thrust (what gives better speed stability after corners) but especially we follow recomendation of guy from AXI which tells us to keep away from RPM 9500-10000 where is resonantion frequency of AXI 2826 rotor. And looks like it works, because since I fly them, I did not change bearing on my ONE AXI. I am not sure how many flights it survived but it is 2 years, so must be LOT :- ))) .. I see only small axial free play, but motor runs very smooth at aproximately 11 to 12 000
And newly I got even newer prop with limited moment inertia, but it is not well tested yet, but looks promising.
Regarding 12" props, yes we have also 12x5.5 carbon and I also (and also Alex) also Havran 12"x5.1 wood props (I think Richie K. flies them) both are on picture, but in my eyes it is overkill, 11" prop works much better in wind especially in figures where model flies against the wind like hourglass, vertical eight and 4 leaf, and also allows tighter corners. But I note I am speaking about MY model, it could be different on another model.
And regarding LH props (pushers), I believe RH is more compatible with models we fly (flying left with LG down and wing under thrust line). May be I would think about it on inliners.
So my conclusion - if I have to chosse from your props, it will be definitelly that your 11x5.5 :- ))))))) ... once again - for my model and its setup with 6 cells.