In a way, I guess I can be a reference for Jarco.
I have NOT purchased an engine from them, but because I have purchased a number of items from them in the past, I asked them who they recommended I use to machine my motor. The gave me the name of the shop they use in Canton, GA. Those guys told me that Jarco sends them alot of 7m's for rebuild, so that at least they are familiar with them,
and I had that shop do the boring/honing, and head/block prep for a MHG. No complaints from me. Not that this means a hill of beans about Jarco's JDM motors that come to you straight from a clip, but I like their operation(or what I experienced of it).
PS- I read some of their Ebay feedback- of 7500+ transactions(~97.5%), there were 5 negatives, and I found 4 of them. One was for a guy who complained that a part didn't fit his car, but he admitted that his wasn't the car that the part was advertised to fit. The others, however were all about JDM wheels that were either scuffed worse than advertised, or bent. So I guess that could be questionable.