Which sidemount harness is best for the really low stuff?

[inverted_bear]

I know a variation of this has probably been asked a million times. However, I couldn't find a good answer in the search bar. Which sidemount harness do you think is best for the smaller stuff? I'm currently diving back mount exclusively, but I'm looking to ease into some sidemount. I won't be doing the low stuff for a (long) while, but I'd like to start out with a rig suitable for it, so I don't have to learn a second rig for it down the road. What would you all recommend that I look into?

Thanks