I have the Harris 6-9 (and 9-13 and 13-27) with direct Arca adapters and they are my go-to bipods for PRS. I also own the Atlas PSR, but I haven't even bothered converting it to Arca. I think the Atlas is a great bipod, I just much prefer the Harris still.
And, as already mentioned, that's pretty much the 2 answers you will see, with maybe and Evolution EvoPod thrown in here and there (also a great bipod).