Annie is it the overlocker part of the Elna that causes you the problem?
The Janome is coverstitch only, I have the 1000CPX which is simple to thread. They are, I would say, not much different from a regular sewing machine to thread, the looper is nowhere near your needles as it is with overlockers.
For me I'd buy an air threading overlocker rather than a coverstitch one with air threading or the Janome 2000CPX which is £499 in J Lewis. Maybe the dealer would part ex for that machine?