It's a mix. You need 275% recharge which is, conveniently, the same as perma-Hasten. So with that in mind you're looking at 95% from enhancements in the powers, 70% from Hasten and 20% form superior Conditioning. That leaves 90% you need from IOs.
Getting 90% from IOs is easy if you've got the Inf. Five 10% bonuses and 4 LotG Globals gets you to 80% easily (if expensively). The last 10% can be picked up easily enough with a couple of Positron's Blast sets. Doing it without Purple sets is a lot harder since you have to pick up a lot more 7.5%, 6.25% and 5% bonuses.
It varies a lot depending on the enemy groups. In general the Disruptors and Patron Pet are tough enough to manage against regular enemies. The Spiderlings have a lower survival rate but they also recharge a lot faster so assuming you've got perma-pets on the other two you can afford to re-summong the Spiderlings early if necessary.
It can also be worth slotting the Pet Defense auras to stack with your defense to help keep them alive. Additionally once you Incarnate your destiny power is good for keeping them alive with either Barrier or Rebirth.
For a crabbermind what incarnets do you suggest I take for each of the slots?