H1B Visa Question

Hello,

My prospective US employer has submitted an H1B visa application for our new job in the US. The visa doesn't become active until the 1st October.

I am planning on using the VWP (I'm British) to head the US early with my family and setup shop. Getting a house etc. Hopefully in July.

My wife is South African and requires a B2 visa to visit the USA. I am concerned that if we apply for that visa the consulate in London will ask her if she intends to return. Now the fact is, she won't be intending to return immediately because from the 1st October she'll switch to the H4 visa. Can anybody cast some advice on what to do? Do we simply arrange an appointment at the consulate and explain the situation. Do we first of all wait to see if we win the H1B lottery?

Any advice would be super!