Digital BW, The Print

Sorry, this title sounds like a stupid "Which digital camera should I
buy next, please tell me" - I also don't intend to stop using the 2100
- it just works very well with its UT7 set of inks.

However the wish for bigger prints is there, I am so far a pure
amateur, so financially this is not very rational anyway, as printer
prices beyond A3 go up very steep. 

1. Stylus 4000: My question - from A3+ (2100 maximal print size) which
is 42,9 cm large to A2 (42cm large) this is not that much a
difference, however the 4000 is much more expensive, and a very huge
machine. Actually I think the 4000 is too big and overpriced also.
Couldn't they just have built a A2 version of the 2100? Same machine,
just wider, for around 1000 USD?
2. Therefore, a good refurbished 7600 seems not that much bigger (as a
machine), however the print size is much more than the 4000. I
probably would start (on both printers) with UltraChrome inks and
would later change to UltraTones.
3. The new HP printers seem less huge machines, outbackphoto has had a
small review, not uninteresting, the question remains the long term
price of ink/ papers, there won't probably ever be a archival solution
because of different print head technology - so far no RIP supports
them, or do I overlook something? 

What are your thoughts on the 4000 being a large format printer versus
the 7600?

Thanks for your thoughts in advance.

Bernie