Let's recap. regroup and reconnoiter (I always wanted to use that word in a sentence)
Current status: You are not using Matte ink (MK), You like Epson Premium Luster Paper, You have tried three or four others covering a wide price interval, Image differences are difficult to detect, the weight of the paper improves your perception of the overall quality, you use every size known to man, you would like to narrow the selection down to a manageable number of choices, you are willing to consider less "well known" brands, you have used the words "very smooth" several times--Without further confabulation (is that a word?) let's formulate the final solution:
Approximate size of paper universe is in excess of 50, other variables include, weight, surface texture (here we go with that smooth again!), thickness, optical brighteners, tone (warm vs cold), price per unit of production, availability, longevity, base (e.g baryta, plastic, wood, silk, canvas, silica, cotton, polyester and fiberglass), shelf life and manufacturer's warranty, manufacturer's financial condition, financial condition of the United States, your financial condition, your Bank's financial condition...(sorry I'm still suffering 401K:itis).
That leaves about 500 things taken 15 at a time or 500 factorial divided by 500-15 factorial which unfortunately is a number larger than the current Bailout numbers. May I recommend the following:
Use the Epson for proofing, Print for sale and portfolio work on Harman--They have both a warm and cold tone paper in both matte and gloss--E Voila! Michael Reichman and Brooks Jensen are both using the Harman for their portfolio work.
There now wasn't that easy--You owe me big!
Utah