I have taken the liberty of moving your question to the Pregnant Cats and Kitten Care Forum. You may get a better response there.
Kittens should stay with their mother until they are at least 12 weeks old and/or have had all three of their kitten-series vaccines, are eating and using the litter box consistantly on their own, and are healthy, well-adjusted and social towards people.
If you have a local rescue or no-kill shelter in your area, it may be best to check with them to see what suggestions they have for you.
There are also some very good suggestions in this thread:http://www.thecatsite.com/forums/showthread.php?t=81700
under the Rehoming Kittens section.