Welcome to the forum MistressNomad, You are probably going to want to find a 4/8 or 5/8 2 inch long blade with a round point to get you started, I shave my legs with a straight but I do still use a DE for my underarms. I would keep my eyes open on the classifieds here for a shorter blade razor or there are several guys here that are able to modify one for you. I would be leary about ebay if you are not sure what a good blade is. You can get stuck with junkers real easily.
As to lubricants, yes, they will work and you have the added convenience of not needing a brush, but I would encourage you to eventually get a brush and a nice soap or cream, It does add to the pampering experience.
A belt will work as a strop, but it is recommended that there be no stiching along the sides, Needs to be totally smooth, Jean legs have been known to work well as has old seat belts.
Let us know if you have any other questions and we will see what we can do to assist you.
Good luck on your journey