I recommend the Sprint. I still love to fly mine. It has a lot more room inside it than the Excalibur. But, the Excalibur will be a little faster with the K85 as the Excal is a bit more aerodynamic. A K85 will not push an XL very well. The Sprint and Kingtech manuals are very good. But none address the Rxer, power distribution system, etc. So ask a lot of questions.
There will be a bit of a learning curve, especially if you are on your own. Best to link up with experienced Jet Guys now as you will need a waiver to fly it and they can help you with info on assembly, operation, etc.
Best to stick with a trainer so you can learn to deal with a jet before putting a lot of $s into a sport jet and crashing before you learn the essentials. However, there will be a leap from the trainers to the sport jets and another leap to warbirds.