I presume you have already paid Pilgrim a visit, so my advise would be to go along to the AK factory and meet the people you would be dealing with if you were to chose this model. As far as if it was a good AK or a bad Sumo
It takes quite a bit more work to set up a Sumo well from what I have read on this forum with all the mods that some people have to do But with most of the other makes these mods are not required and they can be set up well if care is taken. HTH
An AK will cost more to build but should be worth more once built provided it is built well. Ease of build I would say the AK is easier but MikeT would be a better person to talk to as he has built both.
AK good choice of kit by the way ( before any one else gets in )