BEES: Blue Orchard Mason vs. Japanese Hornfaced
I'm interested in obtaining some bees to pollinate my fruit tree orchard. After reading a bunch of information on the internet about different bee options, I'm confused as to whether there's an advantage here on the East Coast (I'm coastal Maine) to going with the blue orchard mason bee (Osmia lignaria) over the Japanese hornfaced bee (Osmia cornifrons). What I've read is that the hornfaced bee reputedly can do an even better job than the orchard mason bee with the number of blossoms they can pollinate in a given day. I'm having difficulty however finding folks in the Eastern US who are specifically using this bee. Most folks using either seem to have chosen the orchard mason bee. Is there a reason for this? Would anyone be willing to give me the run down on the pros and cons of going with each? I'd love to give the Japanese bee a try if I can find a reputable supplier of the bees. The few whose names I've Googled seem to be out of business. I hope this isn't a bad sign. Any suggestions?
Also, once my trees reach fruit bearing age, I'll have approximately 7 acres that will need pollinating. It would be good to get an idea how many nesting blocks I'd need, how many bees and how far apart the blocks would need to be spaced.
Any/all feedback greatly appreciated. Thanks!