Firstly 8 weeks is really too young. They should be 10 weeks at least. And if you're not home all day then you should really either get an older cat or get a pair of kittens, as young kittens get very upset and lonely on their own.
Do not buy a kitten. This will encourage people to breed their cat when there are thousands of cats being put down in shelters every week as there are not enough homes to go round.
You can find your nearest shelter by going to www.catchat.org where you should be able to adopt a suitable cat/kitten/pair of kittens.