Digital BW, The Print

I need help identifying some mystery paper...

A client of mine wants an 11x14 print and I'm out of inks at the
moment, and because of the logistical difficulties of getting stuff
sent here to Mexico City quickly and economically, I've been looking
at the possibility of just having a lab print this one image rather
than waiting until my supplies arrive. The client isn't especially
interested in the process as long as it's going to last.

At one reputable local lab, they offered me several options:

-Print on H. German Etching using an Epson 4000 and Epson OEM
Ultrachrome inks... for 40 dollars(!). I saw an example and wasn't
very impressed with the dmax or what seemed to be the very warm tone
of the paper (nothing against warm paper, just not right for this
image). I don't know whether it's even necessary, but it also seems
they don't brush the paper before printing.

-Print on the same 4000 using the same inks but using some
unidentified Epson roll paper with a lustre finish (which they called
matte, but it's a kind of bumpy RC look)... for about 7 dollars.

-Print on Fuji Crystal Archive paper using a photochemical process.

I asked them to make me one each of the last two, but I was wondering
if anyone can help me identify this mystery paper so I can determine
the print's likely longevity. The technician, obviously not an expert
in inkjet printing, tried to convince me that the print's longevity is
determined solely by the type of inks used (UC) and has nothing to do
with the paper. (Ummm....)

I asked 3 people at the lab and none of them could tell me which Epson
paper it is, just that, you know, it's photo paper made by Epson. They
had several rolls of it on hand, but none were in boxes, just wrapped
in plastic.

Any ideas as to what this paper might be and how archival (if at all)
this print will be?

Peter