may be the way to go with this project. I whole heartedly agree with the other responses about the removal of the existing vinyl. Another option is to screw the floor well into the joists and install wire lath and sand mix mud bed over the existing flooring, then tile. This can be a tricky job and is probably best left to somebody that does it for a living. I disagree a little about the size of tile, today porcelain and glazed porcelain tile are very hard and resistant to cracking, 8 x 8 tile may date your house, 12 x 12 is more 'current'.