Creating a template that provides the parallax effect of the example you gave, and is responsive to various screen sizes, is not a problem.
Converting 60 websites is a significant amount of work. Assuming I can develop one theme that serves practically all of the sites, and further assuming I have access to all of the original artwork and copy on the original site, it still is going to involve several hours of work for each site to convert it to WordPress and test everything.
My bid is $125 PER SITE. Milestone payment of $500 upon completion of the first site (for the up front work and theme generation). Milestone of $125 for sites 2-5, and then milestone payments of $625 for every 5 sites thereafter.
ABOUT ME: I am a Midwest USA based WordPress designer and IT professional, with 25 years experience.
I look forward to talking with you about the specific needs of your website and developing a project plan and timeline.
The portfolio in my profile on this site shows examples of my website design work.