Man, I wish we'd had something up about this sooner... not that it likely matters for the vast majority of you reading, but still.
A discussion with Auto brought up the annual gathering of model kit creators which ended just earlier this week. Apparently, the Hobby★Rock table at the 2015 WonderFestival had a ton of great Rockman doujin model kits available to those with the money to hand them over.
You can get a glimpse of what was available in the image above (that doesn't even represent everything), but you'll want to visit their website to see not only the full assortment, but also numerous images of each (as well as the full versions of each illustration in the banner above)!
With the event over, Auto notes that whatever leftovers the creators have are usually sold on their websites (the URLs of which are tough to find), though you might be able to get one from a scalper at a good price on Yahoo! Auctions from Japan.
If you're familiar with the matter of acquiring model kits of this nature, feel free to share your tips in the comments below!