What's up with the 'best' questions posted way too often, bwahaha? What's ideal for me might be a joke to others as better, best, etc. is opinion and not much else. Slayer machines are definitely top notch for what you want out of one, but the design seems to revolve more around lighter roasted coffees so the water pressure/flow rate can be manipulated to make some coffees more palatable. The current trend is around flow profiling, pre-infusion, etc. and the main reason is most coffees roasted these days are simply underdeveloped and typically quite sour for the most part. Some I've seen others try to enjoy would be more along the lines of toasted, not roasted. Anyway...
If you have the countertop space for a Slayer and can plumb in as required, run what is likely a 240v connection to power it (I could be wrong on that, not sure but some machines can be power hogs), don't mind paying a buttload up front just to have one, as well as long term updates/maintenance just to have quality espresso then have at it. For my taste I'd say invest in a quality manual lever like the Cremina, a quality hand grinder and you will get the best possible end result with some time/effort applied. Keep in mind that the most important change any of us can make is the COFFEE being used as all else depends on that single variable. Then balanced water and so on.
Thing is in modern society some tend to think buying big guarantees a better end result, but hardly the case with coffee. Skill/technique, then coffee, equipment and water is a pretty good balance of how things will fall into place.