Build a website

We have a library management portal (Opensource Koha installation) which is already in use. Koha is a perl based open source software built over the years with lots of features and configuration/customisation options. It also provides a portal for customers but the portal UI is not that impressive and not very customisable as well. We want to give a modern look to this portal with few additional pages on top of what is already provided by Koha. We have got UX developed already for the new pages and we need to get these developed and integrated with the portal. Koha runs on apache web server, mysql server along with perl scripts and hence whatever language which we choose for the new webpages needs to run on the same setup. We will provide a test environment for koha installation (with customer portal running) along with some test data. We will also provide UX pages , static content .for the development of new pages. Initial requirement is to build few static pages with all the provided content & data well integrated into our test environment and then later also get help in deploying it on our production environment. We would also need complete information on the developed pages so that we can support it on our own in future. In total there are going to 7-8 pages