You covered most of the options Greg. But there are a few others if you are willing to make or have a motor mount made up. Have a look on superkids.com in the motor section of ebike or scooter parts. There are several options in brushed and brushless that can be used as a nonhub or middrive.
From spending most of my time in the nonhub section, cyclones can be good if you get the higher wattage ones with an external controller, just junk the mount and make your own. The attachments are pretty average and fiddly for them.
Probably the closest thing to a bolt on kit will be either Whiplashes system, when he has it for sale, or Matt's stuff. Matt has most of it pretty sorted from throttle to controller to motor and mounts. His stuff is expensive, but worth it. The trick is deciding where to mount it and getting chain lines right.
The last big decision with mid drive is whether to drive the cranks or go directly to the rear hub. The direct to the rear hub full sus's I have seen have the motor mounted on the swing arm. The rest of the full sus's I have seen drive the crank to use the rear dérailleur to deal with chain growth. There are of course several options in each of those options as well.
Check out Timma's stuff for an amazing cyclone setup. viewtopic.php?f=28&t=23409
Also, you mentioned the Motoped. Magudaman has done an electric version of one and mentioned working with them to offer it as an option. He has kind of disappeared, or has not posted in the thread for a while. Some one put up a video of it finished though. Looks pretty good. Here is his thread. viewtopic.php?f=28&t=22560
Hope some of that helps. You could have a look at my set up for some inspiration as well. I use a brushed currie driving the rear hub on a heard tail. I have designed it all myself and had lots of the stuff made up. It hasn't been cheap, but I am happy with the result so far. viewtopic.php?f=28&t=19841
Yup, definitely time to get out of the hub section for some research.