The ball joint adaptor sleeves have been around a long time. Not saying they're the BEST option, but DoctorDiff has been selling them for years. They do work for those that can't swing a full brake and UCA conversion at the same time. Obviously it's better to go with large ball joint UCA's in the long run. And I know DoctorDiff has posted here before saying he has SBP rotor options for his kits.
As far as price shopping, make sure you're comparing like to like. DoctorDiff's kits all come with Timken wheel bearings and seals, good quality hoses etc. The PirateJack stuff looks like it comes with the cheapest stuff they can get ahold of. And of course, Cass at DoctorDiff has a long history in the Mopar community and GREAT customer service. Personally I think it's worth some extra money just to know you can call the guy and get help if you have an issue.