The required 30-day notice is usually about all the notice a management company will get from tenants. It would also be rare, if it happens at all, for a management company to agree to hold a vacant house for more than a couple of weeks, if that, without collecting rent.
So, yes, it's far too soon to start seriously searching for a specific house. You can, however, start arming yourselve with information that'll keep you from tying yourself to a one-year lease for a house you might not have rented, if you'd been armed with a little more knowledge.
Looking at pretty pictures of what's available doesn't tell you much about the location nor the neighborhood. If you're moving here to work and don't know anybody, try to make friends with a future co-worker -- or your new supervisor, if that's possible -- who'll add local knowledge to the info a management company like mine sends you.
You might also ask several management companies for a copy of their policy on pets. Not every owner of every house we manage will allow pets, (altho I recommend it and most do), but when you get down to looking at specific houses next Spring, it's good to know what rules you and Fido will be expected to follow.
If you want to contact me outside of this forum with more questions or more specific info, don't hesitate to do so. email@example.com