If I had been you I would be a cat hoarder because I would be a lost cause and have wanted to keep them all. I would also want to grill the adoptees, to the point where it would be like a special forces boot camp, hence not being a fosterer, for everyone's sake. But thats what makes you so special, giving these lttle ones the best chance at the start.
There is a special bond with these, probably because of the injury when they nursed you in their own little way, let alone their super cuteness. Do Elvis and Eva have a family already.