I'd just go knock on the doors of the houses you are interested in. No easy way to do this.
My guess is this is a long shot, but I have seen it happen before. Most sellers can't lease.
They need the money from this house, to buy the next one. That's why I say it is a long shot.
It might be 1 in 50 or 1 in 100 that can do this, but you can always ask. You might have a nice
letter written too with the detials of you and your family, how much you are willing to pay, how long
you intend to stay etc. You can leave it with people you meet, or if they don't answer leave it on the door.
Good rentals are tough to find.
I am working with a buyer- who is looking for lease option too.
If a property is not listed as lease option, I just call the listing agent and ask. I'm finding that really motivated sellers including builders are willing to consider a lease option. call a local Realtor and ask if they can help you.
Best of luck
I wrote a blog on how to find lease-options and rent-to-owns. It's at http://www.trulia.com/blog/don_tepper/2010/03/how_you_can_fi
I'm not necessarily suggesting that for you--though you do raise the possibility yourself. But the situation is exactly the same. You're trying to find someone with a house for sale now, and you're trying to convince them to lease it instead. My blog will explain how to find those people.
To summarize (and read the blog; it's much more detailed), you want people who don't need all their money out right away. Often, the most receptive owners are those with vacant properties. They've moved; they're still making payments on the house but now there's no money coming in. Your pitch, basically, is: "Gee, it must be painful to have that empty house just sitting there, not selling, costing you money every month. I've got an idea that might help. Why don't we lease the home from you for a year. We'll take good care of the house, and you'll get your rent every month. In a year, the real estate market may have improved and you might have an easier time selling, and for more money."
If you like the house enough to consider buying it, your pitch is: "Gee, it must be painful to have that empty house just sitting there, not selling, costing you money every month. I've got an idea that might help. We'd like to rent your house for a year, and we'd even like the option of purchasing it. We'll take good care of your house, and you'll get your rent every month. And we're serious about buying, so we'd really like to have the option of purchasing it, too." Just be careful; Texas has some restrictive laws on how to structure lease-options. But it can be done. Or there's a technique using a land trust that'll accomplish the same goal.
Also, as Naima suggests, another group of sellers who'd be receptive are those with long days-on-market, whether or not the home is vacant. And look for properties that are listed both for sale and for rent.
Anyhow, read the blog.
Hope that helps.
All you can do is ask.
Talking with a local Realtor may help, some sellers may consider renting their homes if the home is on the market long time. Your Realtor may have to call them to learn more about it.
It's not as if people who are selling their homes aren't ever interested in leasing, but those people are few and far between. And, real estate agents (shh! don't tell anybody) aren't always terribly keen on the idea because, essentially, it means the loss of a potential commission.