Hi EM!
I know what you are going through! My hubs & I have been fostering for about 15 years now (kittens, cats) and we find a 'match' for our family about once or twice a year... We have a 'rule' around here... JUST SAY NO... I know that is a simple answer to what you all are going thru, but that works for us.
Once you foster for several months you will understand - you will find MANY, MANY 'matches' for your family. At some point, after you figure your budget, you will find a match for both your family AND your budget. But until then, I would recommend that you wait.
That said, this past September one of our babies that we had bottle fed came back to the shelter (he was a rejected 1 yr old). We immediately went over to see if we could foster him again (he was adopted straight from our home, so he wasn't in the shelter when he was younger). After a week in our home we knew he was a perfect fit for our home. [Our requirements for the addition of a cat/kitten are that he is REALLY laid back, accepts new kittens of all ages (we will continue to foster as long as we physically can) & will be loving & nice to our 2 older cats... Oh, and that he was black. We LOVE black cats & it is sooo much harder for them to be adopted from a shelter than other cats.] He met ALL our criteria. My hubs was actually the one who suggested we adopt him.
For us, we foster about 20-30 kittens EVERY season & care for our 3 cats, too... About 5-6 of those kittens are bottle fed so I am VERY busy at the beginning of their little lives. Some of them are sick, too - so we are doing meds, etc.
The things you need to ask yourself are: can we afford this animal (the average cost per year is about $500 for a healthy adult dog or cat)? Is this animal going to allow our family to continue to foster (will he/she ALLOW temporary 'foster' animals in your home)? Is this animal healthy enough to have other animals in our home? I realize some of these questions you probably can't answer yet, but they are important questions to ask...
Oh, one HUGE suggestion - if you continue to foster, for the first year you work with your group or shelter, you have them have another foster READY for you THE DAY your current foster leaves your home. I have worked with first time fosters in the past & I have found that it is easier for them if they pick up their new foster(s) when they return (or place) their old foster. It helps with the feeling of loss & it keeps you & your family involved with the group.
This, of course, is just one person's opinion. In fact, my husband has OFTEN had to remind me that 'if we adopt ANOTHER cat (we have 3) we can't foster any more' - one way he keeps me honest!
#AdoptingaPet