installing a shower base

Hi,

I'm putting in a shower base - my first one - over timber floors, and i've got a few questions:

1) How to put it down: I've seen a few people recommend laying down cement sheet and using a concrete based adhesive to glue it down. However I've also seen that i should put down a 10mm thick mortar base and glue it onto that. Which one is right or are both ok?

2) If i put a 10mm footing under the shower base, it will sit proudly about 7 mm on top of the vinyl flooring. How do i make the vinyl come up nicely to the shower base? silicon?

any advice really appreciated

Rich