Best is one of those loaded words. For some people best means fastest,
or lowest operating costs, lowest break down rate, or highly archival
inks, or, greatest image quality...
Epson produces some very reasonably priced wide carriage profession
units, which can run either dye or pigment inks.
There 24" model is called the 7600. They get you on the inks, as all
the printer companies making consumer models do.
I think the current list price, inclusive of a 7 (CcMmYKk) color ink set
is under $3000 US (list).
The 44" model is called the 9600, and is about $5000 US list.
The fact that there is no 8XXX model leads me to think a 36" model could
eventually be in the work, but they have never had one and its been
years, so who knows.
I know of a number of people who own them and a very pleased with the
quality of the output and the reliability of the printer. They are
particularly happy with the pigment ink set (there are many 3rd party
inks also available for these printers).
There are a slew of wide carriage products out there. Many use Epson's
heads, or similar piezo designs. Thermal head designs are also out
there, from HP and others. Ink set color combinations abound, including
oranges, greens, reds, blues, etc...
Art