Pfsense is a solution capable to do multiple things . its a security , Load Balancer, Chaching , VPN Server , DNS and many more . also u can buy a hardware with installed application on it or u just need to install it on a virtual machine . the good news also amazon is now offering PFsense as a solution .
If you are looking for a small to medium good caching box alternative to bluecoat , you might think of CACHEBOX . their price is good and it is rich in content such as content filter , caching youtube , and polices . this might be a solution if you dont want to have high end or expensive Box .
visit their site for more info CACHEBOX
Bluecoat can cache youtube videos , for that you need to keep updating the caching policy in your bluecoat into the CPL
bluecoat keep updating their page regularly , even you can subscribe to get notified if there is new policy out there .
you can find it on Bluecoat Youtube Cache