Dan,
I suggest attempting this process in a small bedroom first, to ensure you have the ability to do a decent job. Some other tips:
Attempt to rent a Clarke EZ-8 drum sander. It has a control lever for lifting the machine off the floor. This is a pro feature that many other types of rental machines do not have.
Applying the stain with a buffer is generally easier and uses less stain. But one still has to hand stain along the edges and corners and odd places. My suggestion is do it by hand and forget the buffer. You will be able to control the application better.
If you've read a lot, you surely read that Mega does not compare to Traffic in looks or durability. Granted, it's easy to apply and cheaper. But I have found it does not live up to it's claims of durability. Traffic is a much better finish. But it is about the most expensive and being water based, one needs to work quickly and do a first rate job. Many find using a quality OMU easier until they get the hang of applying floor finishes.
I recommend applying the stain and finish with a 10" Padco applicator. Of course, when staining, you go in 3' sections and wipe off the excess before the stain dries. Using the Padco applicator will allow to screw it onto a broom handle and it will handle the edges and corners as well as the field. It will work fine for small and medium size areas and is MUCH easier to control for the DIYer.
http://www.padco.com/