The easiest airframes to learn on are the Reaction 54 and the Boomerang.....you want scale? -the PST Panther!

None are speed demons, nor intented to be. There is lots to learn about flying jets without adding a high energy flying anvil to the list. Starting, care and feeding, throttle response, safety, support equipment, shut down.....oh, yes....landing....that is a big hurdle too! Put it all in a (relatively) docile airframe til you get comfortable with all aspects, then you can move on. There are more advanced jets with sparkling performance that will take you from there... but walk, before you try to run.