I have Genymotion and VirtualBox installed on my Ubuntu 15.10 with which I can explore almost-all the mobile android Operating Systems.
I am very much exited to try out Ubuntu touch in the same way before I buy an Ubuntu phone.
So, Is there any official links to download "Ubuntu touch" vmdk/iso for trying on VirtualBox (or on any other Virtualization software) ?
The 'Canonical' way to run Ubuntu Touch in emulation is to use the ubuntu-emulator rather than VirtualBox and friends. If you are using Trusty Tahr or later run the following:
sudo apt-get install ubuntu-emulator ubuntu-emulator-runtime ubuntu-emulator-images
Then you create the emulation:
sudo ubuntu-emulator create just_testing
There will be a reasonable download and then you can run your copy of Ubuntu Touch in emulation:
ubuntu-emulator run --scale 0.75 just_testing
The --scale 0.75 option can be varied to produce the 'phone' size of your choice or even omitted completely if desired. Another option to manipulate is --memory 720 which specifies in megabytes the amount of memory available to the emulator.
A screenshot of all of this running on my own system:
References: