Lee's "Modern Reloading" is priced cheap enough, like most of their products, but that's where their advantages end. Their data, which is taken from other sources, is based on "their" equipment. Look closely at their starting loads, they will list it in grains and then list which disk or dipper to use to get that load. There are times when the lightest load they can find that will fit into their equipment is the max load. Hence you will have a start load and max load of the same amount of powder, sometimes they are very close. Also the reference section sounds more like an advertising blurb than anything else, and is full of BS about why his equipment is better than everyone elses'. I don't recommend it to anyone.
Manuals by the powder and bullet companies are O.K., but they are aimed at providing data for "their" products. You might not get data for a certain bullet weight or for lead bullets, or for a variety of powders. They do usually cover the loading processes pretty well. Sierra did make a handgun only version a few years ago, and I think others have at times, but these seemed more at making them money by selling two books instead of one, than they did at specialization. Of these, (Sierra, Speer, Hornady, Accurate, etc, etc) I usually prefer Speers manual the most for handguns.
Lyman has made three Pistol and Revolver manuals, that deal only with handguns. The first one has data for cap and ball and muzzle loading pistols, and has a lot of ballistics tables but very little loading reference material. I don't recomment this one either. Numbers two and three are excellent choices. However, there is one possible down side. There have been a number of new cartridges introduced since number three was published, so if you are shooting a newer round you might want to make sure it's in them.
The other Lyman manuals will have some of the same data, their reference sections vary and you might not get as much material specifically for handguns. The nice thing about Lyman manuals is they include data for a variety of bullets and powder and offer data for bullets made from their moulds. They are usually pretty good all around choices, but I was a little ticked off at number 49. Being a .41 mag shooter I went to their .41 mag data section and found they had dropped all their .41 mould designs and, therefore, all their .41 lead bullet data. But unless you have that same infliction, it shouldn't be a problem.