yesterday I found that link of vmware esxi 5 OVF template for ASA 8.4.2 : http://file.karelia.ru/tq36ww/
it was successfully imported to virtualbox and worked with GNS3
few change that needed before launching VM:
1. once imported go to settings/networking and set PCnet-PC II to all used Adapters
2. go to settings/storage and make "ASA-8.4-disk2.vmdk" - IDE Primary Master
3. apply config and open gns3 to add the vm to the "VirtualBox Guests" with enabled console support for it
once you do all the above, start the VM thought GNS.
From the GRUB boot menu, choose the first option, not "shell" and continue with the onscreen instruction.
Once you reach "Booting the kernel." on the VM window, don't panic it is not stuck, open console for it from GNS and wait some time till it boots (15-20sec).
If you want to watch to boot process, just reload the VM with open console
show interface command can cause issues, use show int ip br instead