Congrats...Jekyll...Kewl!!
My recommendation for after run oil:
http://www.pspec.com/details.asp?ProdID=40&category=7
The main thing is no petroleum based products in your YS as it will wreak havoc on the silicone diaphragm and o-rings...
I've heard of others using the lowest viscosity Mobile1 synthetic motor oil as after run oil also...I've never used it personally...There are a couple other threads lingering around here with more comments about Mobile1....
Chuck