No HP Matte Litho-Realistic ordered for some time so can not comment whether/where it is available. To test the availability best would be ordering through HP's web links to distributors.
Right now I use the paper alternative already described in this thread. I did test a 270 gr/m2 25 % cotton "art" paper that is twice the price (so an inexpensive art paper) but the image quality is not as good and the paper tends to warp on ink loads like you get with the normal profile target printing.
I rely on users that send me new paper samples to extend the SpectrumViz list and keep it up to date. No packages fell on my doormat for quite some time. Photokina 2014 might be a source but I can not promise I will attend.
--
Met vriendelijke groet, Ernst
http://www.pigment-print.com/spectralplots/spectrumviz_1.htmApril 2014, 600+ inkjet media white spectral plots.