Wow this one blasted off !!!
Murph, I gotta ask you why these two bikes?
Because you are comparing Apples to Oranges.
A Busa is a Ponderous bike - a straight line machine - the bike world's equivalent to a '69 Road Runner or a '70 Hemi Cuda. Put it on the straights and off you go like a rocket ... but fawk stay the heck out of the twisties.
Then you've got the Duc ... which is more like a 911 porsche. Maybe not quite as fast as the other but will tear it up in the twisties.
And the two week course you are taking - Is it a track/race course? If so, you're probably going to be leaning towards the Ducati in terms of the handling characteristics of the bike. It turns faster and brakes faster - A much better setup for the track. Of course it IS Italian... which means it's going to require a little extra attention and TLC, but there IS an aftermarket to mitigate much of the general maintenance that a Ducati needs.
If you are not one to take care of a bike and do regular checkups, the Ducati is not for you.
If I may make a few suggestions -
Other straight line performers like the V-Max and the V-Rod will be more suited to the riding style you are getting into on the street with the Harley. If speed is your final objective, then the v-max can be tuned for outrageous horsepower. All of these bikes, however (The 'Boosa included) are NOTHING like the dirtbikes you are accustomed to riding. They have the maneuverability of a 747 ... especially at low speeds.
Other track-oriented performers, like the R-6 and CBR600 can get you going before you make a full-on commitment to a Ducati. (The Honda RC-51 is a good v-twin bike that won't run you what the Ducati will, but has many similar characteristics) Another bike to consider if you like Italians is the Aprilia Mille. This is an Italian with power and reliability.
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Finally. Before you decide to get a bike, I would recommend that you talk to your instructors at the course you are going to take. I have no Idea what their mindset is, but I would bet you that they are going to tell you that in order to get the most out of yourself and the bike, it's better to develop your skills over time on a bike that is suited to your level of riding experience and practical knowledge.
You seem to be infatuated with speed, which isn't necessarily a bad thing. The speed capabilities of a bike, however, are highly irrelevant. You will never use a bike to its maximum capacity on the street. You might take it up to speed on a deserted stretch of highway once or twice, but first of all, no one's going to be there to see you do it, and second of all, any dumb screw can hop on a bike on a straight and crack open the throttle and hold on for dear life. These guys then typically never shut up about how their bike can do 200 mph ... they know, they've been there.
Hope you're not one of these guys. Anyway. To be the fastest guy out there you have to develop your skills. You can't do that on a liter-class bike unless you are on a track. You can do that on a 250 or 500 on the street, because you can max out the bike's capabilities and learn from it. If you are just looking for bragging rights, go ahead and spend your money on one of the bikes you mention. And Talk. Cuz that's probably all you'll be able to do. There's a reason why all the big names in racing started out small.