Website build

Hello there, I need a quote from you for a website build. Basically its one page site (landing page) with quite complex but simple 3 stage contact form. Please see the jpg attached. So on the first stage of the form you will enter your contact details. The second stage will involve 2 options either pond or aquarium. At this point none of the other stages are visible ( will supply artwork to show this asap). On selecting aquarium option radio button, the rest of the form will display the required fields & options, relevant only to aquarium. If you were to select pond radio button instead, the options for pond will display instead. The options will not be laid out differently accept the tick boxes under services will be more or less etc. On submission of the form. I will then receive an email with all the inputs of the form.

The customer will also receive an email, thanking them for there time, informing them that i will be in contact. terms and conditions will not be pages but pop up div window on the page including which you can open & close.

In terms of language for the form, what would you suggest??
Also which hosting server do i need: linux or windows??

Sorry for the rabbiting. Look forward to hearing your thoughts?

Regards,

Evan