You can use Dexter/Brunswick/generic soles for the HPU, although you may need to trim any of them to fit. The heels have a weird notch in them, but it's not required (I use a generic buckskin one.) The ones for the Dexter THE 9 have some weird lines that may not match up exactly, I haven't tried 'em.
The higher the number on the sole or heel, the slidier it is. S8 is the default microfiber sole and they range from S6 to S10 within the Brunswick soles (I don't think they make an S4, least, not that I can find.) Other manufacturers make lower and higher, although for my money the Brunswick S10 is about the same as Dexter S12.
One caveat about these shoes that if you drag your toe, you'll start to wear out the plastic toe on your trail leg. /u/miseryshusband is my default knowledgebase for all things shoes and pointed me to this guy that you can wear on your trail shoe. I have size 11 and the large fits pretty okay. Otherwise, you really don't have to worry about the traction sole.
I'd also recommend a shoe brush so you can maintain the new soles as well. If you're coming from not sliding, probably want to work up slowly from one-step drills so you don't eat wood.
I also drag my brake toe. This SST8 sole protects the toe of the shoe from wear and is definitely not coming off unless you want it off. http://www.amazon.com/Dexter-Max-Powerstep-Traction-Sole/dp/B009GDHBIQ Side effect, it looks goofy.