The Form Wizard can be styled with CSS but I cannot promise that you can make it exactly as you have styled your custom form.
It provides different css classes per each question type (you must use classes it provides you cannot add your own) that can be used to style questions by their type but currently does not offer per question css classes. You could use id selectors to select specific items but the ids themselves are very long partly because of asp.net and partly because I use the question guid as part of the id, still it could be done.
I would recommend experiment on the demo site creating a form and then copy the rendered markup to a local html file and experiment to see if you can style it as you wish.
Note also though that I do not recommend using the Form Wizard directly inside the layout.master file and do not think it will work correctly like that, it should be added to a page like other features.
When I get a chance I will make VB.NET versions of my Hello World examples and maybe that will help you implement your custom form, but I am extremely busy so not sure how soon I will be able to get to it.