I think you're backwards. Tails is the LiveCD with a browser (that can beacon straight out). Whonix is the VM based system. I think it's capable of more than just browsing, but I use it as the "secure browser" in Qubes as a disposable VM, because it just automatically does the right stuff with the gateway VM and such.
It is an complex idea but in theory one could produce a live-image that spins up the Whonix 'gateway' and 'workstation' virtual-machines into RAM. Boom, probably better than Tails.
The most obvious concern is the RAM-usage (because of tmpfs and each VM having allocated RAM on top of that) and if disk-usage between the gateway and workstation images could be de-duplicated to save space in the live-image.
