Fact is, that whatever route you choose, a good tune is a tune done on the road, not on a dyno. Which means you need a wideband. The 'easy' way is to get a powercommander V and an autotune module, assuming they make one for your 990. Or you get a powercommander and you tune it by hand with the wdeband.
A more involved way is to get a wideband and tune it with tuneEcu, another option is to invest on a motty (which does the V+autotune job, but it does it better), but you will have to splice the harness for that one. Apart from the motty being a very sophisticated piece of gadgetry, it is also transferable from bike to bike and not bike specific like the powercommander.
Probably tahoecr and k2m will chime in promptly and shed more light to this, they are the people to listen to on these matters.