BT and RT Facet pumps are both rated the same as far as GPH and PSI, so I don't know what the difference is if any.
Earls sells a black braided nylon line that's kind of similar looking to original. It's what I plan to use.
http://www.jegs.com/p/Earl%27s/751252/10002/-1
BTW, with two pumps, depending on how the two are hooked up, you can either double the pressure or double the volume.
Larry