Which website builder? Quick but professional

I want to create a website in a couple of days. It's main purpose is to offer a free digital download. I want to capture email in the process, to provide follow-up guidance to using the product. There's no e-commerce involved and few pages (4-5). Analytics and domain registration would be a bonus. I want it to look nice - I'd like to have flexible visual design options or be able to adapt a template. I'm comfortable with the likes