Here is a quick link to a reference for a cheap switch between the blacks. With not using the new Epson inks, I haven't use this method myself, but the poster originally referring to the method has a fairly good reputation for things like this: http://www.naturephotographers.net/imagecr...d=21316&u=21316
For glossy vs matte papers, I have gone the Epson Premium Ultrasmooth route for most of my prints. The reason is very simple, at least for matte papers. Under glass, which is how I assume most of the prints will be displayed, there is not a second reflection off of the prints. The color seems to "pop" a bit more than just holding the print free of a frame.
I actually don't use a fully glossy for my prints - a slight compromise has been reached to use the Premium Luster. I use this for Black and Whites for the richer blacks, portrait work (why - purely irrational reasons) and then if a glossy type of paper is requested. The downside with the previous generation of Ultrachromes is bronzing when the ink laid down is very close to white.
And with staying with the Epson papers: I have tried a lot of papers from various manufacturers and decided that I like the detail in the blacks and whites the best.