First, make sure that your apps meet Apple's HIG -- and the "guidelines" are misnamed -- they are rules. If you're just presenting simple HTML content, don't be surprised if Apple rejects the app and suggests you go the HTML5 webapp route instead, so make sure your iOS app uses the device in some way that can't be done with pure HTML.
You can do quite a lot with Windows 7 as long as you don't need to test in the simulator or test on a real device and are just testing in a regular webkit browser. After that you'll need a Mac in order to build the code, test on the simulator, deploy to a device, and ultimately submit to the app store. /How/ you get that mac is up to you -- you can hackintosh it (not supported, questionable legality), you could buy a little mac (mac minis start at $519), or you could rent a mac server online. Or find someone with a mac to help you. But sooner or later, you'll need a mac in the process.