pumphouse to radium has 1 class 3, eye of the needle, the other rapids leading up to and after are mostly wave trains, scenic and fun. radium to rancho has 1 big class 3 with a hole at the top, the rest is scenic and a few miles of flatwater. the most bang for your buck would be the rancho to state bridge 131, it has mostly class 2 rapids every so often, i thought it was fun too.
none of this would compare to browns, i think shoshone would be more like browns, but pumphouse is scenic.
there are options for rentals right at rancho, but like what others said, you'd get more for your money if you got one from BTC, or Confluence kayaks.