It is still available, but it is now called Harman Gloss Baryta and is distributed by Hahnemühle, although I think the largest quantity is now 30 sheets per box. There is really nothing quite like it. If you want 250 sheet boxes, then you would be looking for something completely different.
I buy it in 17 x 15 inch sheets, and 24 and 36 inch rolls, and haven't noticed much in the way of inconsistency between batches. You could buy 17 x 22 inch sheets and cut it down, that would give you 120 US letter sized sheets from the same batch.