The D2 is the new big brother to the NY121. I understand that it has a superior tweeter. It's quite a lot bigger though, so if matching cab sizes is important to you it may not be the one.
You could also consider the TRV112, which has the same footprint as the combo if you set it up in "portrait" mode.
I would still say that the Marcus head is far more versatile than the LM, so if you can upgrade that as well at some point that would be cool.