Before i start my first grow

I'm going to start my first grow in a few weeks and this is what i came with up that i want to try out.

Soil Mix

Potting soil
Perlite

Will this mix be ok for the first few weeks before i go into Vegative stage?

This is the type of light i plan on using along with the ferts for that stage.

Vegative stage with a 250w MH - Light cycle 18/6

Bio Harvest Grow - NPK 9:2:7

Flowering stage with a 250w HPS - Light cycle 12/12

Bio-Bloom - NPK 2.0-6.0-3.5

I was thinking of buying a 250w HPS with Reflector, the lady at the shop said by buying this ill be able to use a 250w MH for the veg stage and switch to 250w HPS when in flowering. Is this true and does anyone have experience with this setup?

For the ferts, are they a good choice and how does the NPK look for each stage?

If anyone has any tips are helpful hints or just anything to add on this it will be graet.

Thanks.

Remember to spray some bug spray or a good pesticide on the floor and around the edges of the wall. spider mites can show up from no where and do a lot of damage.