I find it odd that someone would recommended flash because of bandwidth limitations. Flash's reputation is not one for bringing down bandwidth, it's actually the other way around. I love flash but even I wouldn't recommend it reading the limited info from your post.

The simple form you mention is web design 101. Your issue may be the fact that you will need to store the information somewhere, which you cannot do with flash alone unless you are building an AIR application on a network. If it's a public website you'll need a server side language and access to a database whether you use flash or not.