Well, I posted more about the Amazons and my findings with them on the Linnie Forum... It's hard to say, both are rather mellow birds. The biggest difference is going to be the talking ability, honestly. Amazons are very outgoing and vocal, where Ekkies tend to be a little quieter and more reserved - they'll learn to talk, but they're like linnies, pretty quiet most of the time. If you get an Ekkie, I recommend a male as the females can be tricky and I don't recommend them as first time big birds - they have attitude, are demanding, and can be nippy whereas the males are out to please (remember, they have to keep the demanding nippy females happy in the wild!
They're about the same size, so housing and food needs are similar - Amazons have a tendency to get fat so watch that on them, and Ekkies have a more specific diet we don't quite understand in the States it seems, they all get overgrown beaks! One customer was able to fix that dietary problem by feeding almonds instead of peanuts and gave no peanuts at all and went from a 3/4 inch beak trim a month to a normal trim every 3-4 months, and she got that poor bird tested for EVERYTHING under the sun, spent thousands trying to find the problem and it ended up just being diet - we don't have as many Ekkies as common pets here in the states as other countries, so we're learning more about them every year.
Now I'm rambling on again!
Really, what is it you want in a bigger bird, Sharon? Think up a list of what you like and what you don't like, and how important certain things are. Is your #1 want in a big bird their talking ability, or cuddling? Do you want somewhere inbetween? Look at your household - do you have a big family? Is it just you and hubby? Can you do a one-person centered bird, or do you need a more 'flock' friendly bird? Think about your other birds too - a bird that might be flock aggressive would not work with your other little birds. Think on that, make a list of what you want and don't, then look into what species, generally, fits the bill
That's what I always told my customers and they were generally really satisfied once they found the species that fit what they wanted - it helped nip the impulsive decisions in the bud.