I think an Arca/Pic/Spartan adapter could be done.  The Spartan cup would sit in the center of the arca portion.  I may be wrong, and have not measured dimensions.  I would consider paying extra to have all three in one rail. 
As it is, I will carry the arca plate with a spartan stud on it.  I considered getting the arca/pic and installing a Spartan Gunsmith Adapter in the stock, but ended up just getting the Spartan/pic rail.
@Salmon River Solutions @Unknown Munitions
Can Santa deliver on that late Christmas request?  If not, you guys do awesome work anyway and I really appreciate the current options.  Figure the worst that can happen is that 
@Formidilosus tells me to stop turning my rifle into a bloody Swiss army knife and that I need to learn how to use my trekking poles with only the straps.  He would be right, I fiddle with too much crap... and now I'm wondering why I even ordered the rail. 

