There are two Premium Outlet Malls in Orlando.....one is on Vineland Avenue, which is just 3.5 miles (7 minutes by car per Google Maps) from the Lake Buena Vista Factory stores. It should be virtually as easy and quick to get to one outlet mall as it is to get to the other. I can't imagine that extra 3 miles would translate into a 2 hour commute, even when using the bus service.
While I have not been to the LBV Factory stores, I have been to the Premium Outlets (both locations in Orlando) and they are AWESOME. We primarily go for the sportswear stores (Nike, Adidas, Reebok, Underarmour, etc.) but there are so many more as well. The Vineland location of the Premium Outlets has a Lululemon. There are Disney stores, Harley Davidson, Columbia, Aeropostale.....a HUGE variety, and definitely worth calling up the outlet website to get a list of the stores so you can see what you may like.
If you are going to be staying in Kissimmee, it would also be worth visiting the Nike Factory Clearance Store. Its a stand-alone store right in Kissimmee, and the deals there were AMAZING. We got Nike Climalite hooded sweatshirts for $10 (regularly $55), Nike t-shirts for as low as $4.19, shoes for under $25, and licensed Florida Gators wear for men for $8. By far, these were the BEST deals we found all week.....and we did alot of shopping!!!