Make our website front end mobile friendly

Our website is a all custom php... we don't have a desire to change our backend as it is integrated with so many of our day to day process.... also we have great site traffic so we are not ready to change the fundamental script of the site we want to make sure google see's it in the same way .... but we would like to change the layout, look and feel of the site ... the good news is we have a great template for what we are trying to accomplish at [login to view URL] this has a layout similar to what we would like... This dev site was developed on a magento backend ... after working with the magento backend we hate it and would like to now keep a lot of the design of the dev site and apply it to our current php backend once this process is complete we would like to develop a downloadable app the functions much in the same way as our now mobile friendly site with a few additional integrated features