It's not that you're using stock photos, it's that you're using very generic looking stock photos. The result is that given your minimal layout the first thing you see on the page are bad stock photos. So this isn't a stock photo issue, but a total lack of art direction. Also there's a larger killer issue:

I've now been looking at your page for a few seconds and don't have a clue what you do.

Maybe you've hidden that info under the fold. Maybe you haven't hired a copywriter yet. Maybe you're still figuring it out. But I have no clue what this website does and why I should trust you with access to my facebook account.

$100k sounds like a great deal of money, but it isn't: So if you're being tight with the budget I get it. However that said hiring a freelance web designer to sketch several landing pages isn't a huge investment. Unless of course this is just a throw away page and you want to spend the money on the real product.