possom - don't use rocks unless they are artificial rocks - real rocks have minerals in them that will get leeched into the soil and will harm the plant.
Make sure the soil they sent you is good - if they sent you a real rock to put with your VFT, then i wouldn't trust it simply because i think they may be looking for your repeat business. The soil you should aim for is peat (Canadian sphagnum peat preferred), and sand (horticultural sand that is washed - make sure it has no extra minerals!) I personally use black-gold brand gardening sand (you can get it at wal-mart, or any hard-ware shop with a garden department).
Stratification is the process of putting the seed through an artificial winter. Keep them cool and dry for a couple months, then put them out so they think its spring and will start to germinate. The problem with that, is your current timing - in a couple months it will be time for everything to go dormant for the winter - and if a VFT doesn't get its dormancy, it will be very weak.
In my honest opinion, what i would do if i were you, is sow the seeds now so they can have a couple months of growing before going into dormancy.