E4UA does offer 2-pin-to-4-pin adapters, but there have been concerns about long-term durability. I'd definitely be open to trying them out, though.
It's worth the risk if one has an investment in 2-pin cables. The durability issues may have been the first prototypes.
Oh, BTW, I noticed the PEARS site has demo units available stated at the bottom of the home page. Can you check if they can swing a SH-3 demo unit your way if your plate clears up this new year.... No rush.