I would use any the following:
Moab Somerset Museum Rag.
Hahnemühle Photo Rag. (My original test print from a few years ago has too much texture, but the paper in my current swatch is not too bad when viewed from 18 inches or more).
Hahnemühle Photo Rag Bright White. This would be perfect it it weren't for its “moderate” oba content. Similarly for Harman by Hahnemühle Matt Cotton Smooth.
Canson Infinity Rag Photographique.
Museo Portfolio Rag.
Possibly Canon matte paper, though I'm unsure of its oba content.
The smoothest papers that are not yet satin:
Canson Infinity Rag Photographique 210 then 310, dual sided exists too
HM Photorag Ultra Smooth 310 grams
HM Natural Art Duo 256 grams dual sided
measured with two thumbs and two eyes, halogen 100 watt at 1 meter.
Some Tecco qualities come close, Some Innova follow. Some Harman and Innova Matt Fibre qualities but they could be obsolete meanwhile. My Museo samples are of the older batches, formulations changed there.
Thinner qualities usually are slightly smoother than the thicker versions.
HP Matte Litho-Realistic is smooth too but may yellow despite OBA absence, my own experience and the Aardenburg test goes that direction too.
Avoid any Bright White paper including the PhotoRag B W, it has more OBA and it does not not hold as good as the normal PhotoRag that has a little OBA.
Canon's samples I have here, EU + USA catalog, are not smoother than the ones at the top here.
Met vriendelijke groet, Ernsthttp://www.pigment-print.com/spectralplots/spectrumviz_1.htm
480+ inkjet paper white spectral plots, November 2012:
rearranged categories, Sihl Masterclass papers added.