Scott, this is one of those never ending debates. OE parts verses aftermarket parts. WE all know MANY RV's, including RV10's, built and flying that are stock. They are safe, reliable aircraft built with the mind set of using what Vans applied to therir prototype aircraft.
There are many RV's that are built and flying with aftermartket parts too. Strictly the option of the builder of course. Many use different engines, avionics, interiors, fuel systems, and yes plumbing systems. Whether these accessories are any more reliable, functional or offer a superior benefit to the aircraft is a never ending debate, and yes some flame wars.
My .02 cents worth is to see what you want out of your plane. Then go see alot of different RV10's. Local fly in's, Sun N Fun, Oshkosh, perhaps even a trip to Vans themselves and see how these planes are the same, and different. Talk to the owners or builders and see why they opted to do what they did. Then compare notes and see if that those options fit in with your ideas.
Tom Swearengen, TS Flightlines LLC
Teflon Hose Assemblies for Experimentals
Proud Vendor for RV1, Donator to VAF
RV7 Tail Kit Completed, Fuse started-Pay as I go Plan