In my opinion, having stripped a lot of paint over the years, there’s no great way to do this – it’s an ugly job, no matter what. As you say, the paint is probably leaded, which means you want to be careful how you get it off – in other words, don’t sand it off and breathe in the dust (but you knew that anyway).
As regards chemical strippers, methylene chloride is about the most effective thing out there. It’s pretty toxic, and a typical cannister mask won’t stop you from inhaling the fumes, though you won’t smell them. There are a number of brands you can buy, and my understanding is that the price is related to the amount of methylene chloride in the product – meaning the more, the pricier. You can also tell by weight – the heaviest can has the most methylene chloride. In my experience, methylene chloride is good against modern paints, not so good against mid-19th-century paints.
Another option is to use a heat gun, and then clean up the residue with stripper. I’ve done this some, and it’s not a bad method. I don’t know how much lead might be volatilized by heating up the paint, but I would assume some. You don’t want to catch the paint on fire, but you do often get some burning. Try not to char the wood – it’s easily done, unfortunately.
The one product I haven’t used is Peel-Away, which a number of people have recommended. There are two types, one of which is basically lye in a paste – this is the type that’s said to work. The other version – the kindler, gentler version – I suspect works about as well as other kinder, gentler strippers – in other words, not very well. Of course, the lye type is caustic, so protect yourself. It’ll also darken certain woods, and damage anything else it gets on. But it does get paint off, or so they say.
Good luck with the project.