Is it really necessary to have everything on https? What kind of information are you collecting on this lead form? Most people won't bat an eye about you collecting things like name and e-mail address on a non-secure connection, but it would depend on your customers and industry. For the visits you're getting now, are a higher percentage submitting the lead form because the pages are secure? If not, I'd flip the URLs back. https is slower and the browser won't be able to cache everything, so it makes the user suffer on every page load.
A few other thoughts (it's impossible to say without seeing your site), but having a lead form on every page may be overkill. You could just link to the form (and then have the form be secure), or you might find success collecting just the e-mail address on all of your pages, and when you collect it, have that go to a secure lead form. Then you'll have a chance to e-mail market to those who abandon the form. Something to think about and maybe A/B test.