Site Build It has a 'Form Build It' system where you can make contact us forms with autoresponder systems etc.
Regarding flash, if you can produce javascript/html code and simply paste it into the web page, then this isn't a problem. If you're uploading your own html and not using the Block-builder system then you simply need to work around your HTML editor.
A word of warning with flash .. they look good (usually

) but they lengthen the time it takes for your page to load. In the online world where more than a couple of seconds is 'too long' you'll simply be bouncing off potential leads. You have to cater for dial-up and mobile broadband users too! I was bidding on eBay this weekend with my USB dongle - took ages!
Substance over style - take care over your content and the rest is simply detail. Good luck!