Yes you can do it in 8 exams.
The length of time needed to pass the exams will depend on how much knowledge you already have on these topics, as well as how much time you can put into studying.
If you don't know the topics very well, and you don't have much time to study then it could take a year or two or more. If you have been a systems admin or systems engineer for years already then you could pass the tests in a couple of weeks with minor studing.
In theory if you knew all the material (and you didn't like your self very much) you could to all the exams in about 3 days. A Couple of hours per exam, 2-3 exams per day. Granted most people would rather kill them selves than put them selves through this kind of knightmare.
How much experience do you have? These exams are not easy, and are geared for people who have been in the field for several years.
Denny
MCSA (2003) / MCDBA (SQL 2000)
MCTS (SQL 2005 / Microsoft Windows SharePoint Services 3.0: Configuration / Microsoft Office SharePoint Server 2007: Configuration)
MCITP Database Administrator (SQL 2005) / Database Developer (SQL 2005)
--Anything is possible. All it takes is a little research. (Me)