ATCs: the active or passive versions?
I would go older passive 20's second hand or 35's (rare) for a modest investment to see if you like the more forward presentation. My concern would be that with the 20's you will want or expect more deep bass and this will require a sub. Not that the 20's do not have bass - they do and it is very punchy or fast - a pretty convincing kick drum...but they certainly do not do the bottom octave (20 to 40 Hz). If you get hooked on the sound then plan later to eventually upgrade to an active version. If not you have not lost too much in terms of an experiment. The forward presentation will take a while to get used to but it seems to be what you are seeking.