Hi Andy,
There are many compressors as Dave said, which can achieve similar result. Cheaper ones would normally have simple controls such as Level, Tone , Attack, Sustain. And they are normally compact pedals. The more expensive ones would give you greater control such as compression ratio, the knee, threshold, etc but it can be confusing to set up..these are normally rack units.
Having said that, compressors at Abbey Road had very little controls. Prior to 1964, Abbey Road used Altec compressors which only had 3 controls (input controls, output attenuator, and recovery) which I believe was one of the elements of the Shads early records ( as well as The Beatles). The sound was magic indeed! you don't even know compressor were applied into virtually everything
Then, on 24 January 1964, they put Fairchild 660 compressors into service. These also had 3 simple controls. These are one of the best compressors ever made if not 'The' best. I've listened to it in action, and I almost cried
So, I would say any descent brand will do adequately.
Try to put a compressor after the echo, see how you like it. Maybe turn down the echo a few notch below what you normally set, because compression tends to bring the echo level up.
My two cents.
regards,
Robby