BindTuning themes work on Kentico 8/8.1 but they are not yet optimized though the installation process is the same as Kentico 6 and 7.
I suggest you first download our free theme, TheBootstrapTheme: http://bindtuning.com/cms/kentico/kentico-6/theme/TheBootstrapTheme or download a trial theme.
After the installation you will probably need to make some adjustments on some areas. If you need our help we will happily help you. :) Here is the link to reach us: