the last two options you have mentioned might be best.
I feel that from frog rock rapid down to the bv play park or through to the browns canyon put in would be a step down from browns at these levels.
class 3 for sure, with swift water. I would look at the whole BV playpark before putting on, if it looks like fun, then from frog rock down would be a good warm up leading to the PP crux and then slowing back down as you get closer to the browns put in, your take out.
If the BVPP looks like a big step for the beginers, I would look at the big bend run. It will be a step down from what you saw at the BV park, and is a longer run if you go all the way to salida.