Need an accelerator - WAN? Application? Suggestions?

Hi,

I am sent to remote locations and where my team and I rely heavily on Google Earth, GIS data and tons of fillable forms. Often we are operating on a very slow VSAT in the middle of nowhere. To speed things up I installed a Synology NAS server to keep all the forms so users don't need to go hunting on the internet for forms if they didn't already have them installed on their laptops. I also keep old forms as examples so people see how to properly fill them out. I also installed a Peplink WAN balancer so that if we have 2 or more wan connections I can bond them together and improve the user experience. Finally, I was told it would help to install a WAN accelerator but when I called Riverbed they said they did not have a product that could do what I needed, basically cache our Google Earth images and GIS info so each user didn't have to download a fresh copy of the same stuff over a slow internet link. So smart people, any recommendations for an accelerator? Would it technically be called a WAN accelerator or a Web Application Accelerator? Also, do you think the firewall installed in Peplink Bal380 is 'good enough' for most common attacks or should I look into a dedicated firewall appliance? If so, any recommendations on a firewall that is super easy to configure and max 1RU height? Thanks.