Hopefully some sister ship owners can advise you on particulars.
I have replaced almost all of the original gray plastic water lines, after having a leak develop at the pump fitting. This was the "Qest" product.
I did keep the EY-fabricated manifold under the galley counter, for our two tanks.
You may want to map out some new routing for the lines; we did that. It's fiddly work, but not very technical. I doubt that sole removal is involved... have you looked under the edges of the existing sole with the access sections set aside?
I did end up moving the pressure pump and adding an accumulator. If I were to do it over, I would spend the extra $ for one of new newer pumps that vary the pressure and seem to obviate the need for the accumulator.
Here is the thread from our plumbing project:
I am in the process of replacing most of the fresh (potable) water system in my 1988 Olson 34. This is the gray flexible tubing that Ericson used, along with thousands of homebuilders and RV manufacturers in the 80's. I had a persistant drip near the pressure pump. A local RV parts distributor...
ericsonyachts.org
Hope you are soon raising your glass of clear and clean water for a Toast!
(and that none of your crew throw toasted bread back at you.... !)