I can help you out a bit on altering your suspension.
First: Lowering your bike and in essence flattening out your swingarm does indeed increase the wheelbase but it's so minute it will have NO noticeable effect on handling. The adverse effect is due to the swingarm angle itself. Swingarm angle is a very important aspect of the bike's geometry. Often overlooked by backyard suspension experts.
The number one adverse effect of lowering is you have now restricted your available lean angle. The busa is already restricted by the wide girth of the engine. This is compounded by lowering.
I'd suggest you leave your bike at stock height and this is why. Lowering and or stretching limits your bikes performance capabilities and thus limits the riders ability to advance his skills. A lowered bike also limits the suspension travel and can get you in a heap of trouble in some situations. Clearance problems is another issue that must be addressed.
Your busa is capable of performing quite well with the suspension totally stock. There is a price to pay for big geometry changes and none are good. Do your homework before making the decision and enjoy the ride no matter what mods you make to your busa!