looking to build a rpt

Hi All,
I'm thinking about building a 3d printer, but got stock on the
software to generate the slices from .stl file.
boxford Rapidpro can do it( like the demo, and it costs around L
495.00 ),but the countour layers should be cut with a vinil cutter and
then assemble the model by hand, no, no mistake here, I realy wrote BY
HAND ( think about those 100's of layers :-( )
Has anyone try it ? or know of a software to slice stl and output
the slices as a bitmap so it can be printed?
I'm geting tired of using my router to make those thin wall
prototypes, it takes a lot of time to get the parts out.
It would be nice to have a 3d printer, just let it printing and go
do something else with the router.

Fogassa