Indeed, the power tree is a good choice because it increases your damage to make your combos more effective on mobs. Personally I would choose the power tree over the crit one, because you can have crit damage enchants with gloves/pets, so it’s not really necessary unless you want to rely on luck. Choosing the power route gives you major bonuses, like extra 150 damage, Strength increased by 30%, 10% more accuracy, and having a chance of 10% enemy def gone. Crit route has a 10% evasion bonus, and 20% damage reducing skill, and the max HP upgrade 30%. You could max out the power route and have some skill points left over to add onto the power upgrade, to get the 30% more HP bonus, if you’re going for the power route. But it’s really your preference if you prefer having high str / damage or having good crits / def /evasion.
For armors, hunting sphinx may be tiresome, so try getting 2 pieces of it to get the def bonus. And the rest of the armor you could have regular one, so that keeping the def bonus and the regular armor you save money and time. Once you hit around level 100ish you could buy 2 pieces of the Machine set, (Machine+2) and repeat what you did to the sphinx if you want to keep the def bonus. The reason to this is that you save money and don’t have to waste time hunting for equipment. Once you get to 130s you may do the same or go for the full MG set, switching out with normal equips if you want to save money; but at around 155 there isn’t really any good regular armor so then you could try to wear the full MG set at +2. The enchants are up to your preference, str/stam is a good choice.
For info check out this link on Mei builds: