1/2" aluminum is a big ask for a small welder. I TIG a LOT of aluminum, and my Syncrowave 350 would struggle on that.
You're gonna need a big machine for that kind of work. No way a 200 amp has the nuts.
Technically its possible with enough preheat and the right joint design, but in reality that's asking for trouble. There's just too much thermal conductivity to overcome.
If you're only realistically going to weld 3/16 and under, you can get away with a 200 amp power source.
IMO, aluminum over 3/8" is wire welding territory, and anything really super thick gets friction stir welded or some other heavy industrial process. I want to say my Millermatic 350P is only rated for 1/2", and that is an industrial 350 amp power source.
Aluminum takes a lot of energy to weld. How big of service is available in your shop? My Syncrowave is on a 100 amp breaker. An inverter will draw less, but you're still going to want a big circuit.
As far as what BRAND of power source, I don't care for ANY brand of machine or tool I can't get service and parts for from a local dealer. That goes for welders, hand tools, machine tools, cars, outdoor power equipment, anything. If you are willing to roll the dice on a welder that you may or may not have support for down the road to save a few bucks, I commend your bravery. All mechanical things break, its just a matter of when. I like stuff I can get fixed when it breaks.
Everlast has the reputation of being either the greatest or a hunk of junk. Seems like you either love them or hate them.
If that's all you can afford or justify, then buy it and start welding.
If you can afford it, I would recommend looking a little farther up the food chain, especially for aluminum TIG work. You'll be happier in the long term.