Hey there,
I use instapage for my landing pages. It is freemium, but the basic version is $29 a month, but you can design what your page looks like on pc, and also make a mobile version, with A/B split testing features. After your visitors submit their information, you can redirect them to a thank you page where you may set up a timed redirect to your SLO for your ROI needs.
If you would like to, I can send you a refferal link via PM, and help you out with building a better converting page.