Yes, if you're going to poly bushings I definitely think you should get some adjustable strut rods.
The "adjustable" name kind of gives a false impression of them. It's not that you need to adjust them all the time, you really just set them once. But the ability to make them the correct length is important, especially when you start changing things. But even if you're stock as a rock, the factory strut rods don't work perfectly for every car, they're just "close enough" for production. And keep in mind the factory alignment specs and bias ply tires are a far cry from radials and more modern alignment numbers.
If you really wanted to, you could build a set of non-adjustable strut rods and just size them to your car, since you're really only going to adjust them once (more than likely, unless you change suspension components again later). But it's probably a lot easier to just buy a set of adjustable strut rods.