I have only ever seen this one 20xl motor for sale.
I would personally like to see any of the xl motors above the 14xl. They look like a great alternative to the higher end motors. I have had great success with the lower kv l can motors on 5s and higher. I can only imagine how well the lower kv xl motors will work. It seems like their design and constuction shortcomings are amplified less by higher voltage. I am guessing they work better with less current running through them.
Sike, I will use a rc monster heatsink/clamp on the motor, I have a feeling that will do enough.
Oh, and about those connectors. I have decided to just hard wire my motors. I have plenty of motors and speed controllers so I just hardwire them up and they work better, or at least they do not develop problems later on. Had too many issues with the 4mm connectors, and the 5.5mm connectors are too big, and look funny, just my asthetic side talking there!