Here is a link to one property in Woodbridge well within the hour commute:
You can go further south and or west of the Lorton area but it doesn't take long for you to exceed an hour commute. As you may not know the Lorton area will be part of a major influx of personnel in the next year due to relocation of jobs to Fort Belvoir and the new NGA facility a few miles away in Springfield. Traffic patterns are going to undergo a big change. Perhaps your husbands new job is part of that influx?
The good news is if you are working close to Lorton Station you could go as far south as Fredericksburg VA and ride the Virginia Rail Express into Lorton, This may be your best bet for affordable horse ready properties on acreage. The drive could push your hour limit if you are driving during major rush hour traffic but depending on your husbands ultimate location in Lorton. So you need to be prepared for our traffic.
If you would like to email a list of your requirements and price range I'd be glad to send you properties that might fit your needs. It is hard not knowing the area and trying to look through the MLS without knowing the commute patterns.
Generally you need at least a 5 acre lot and depending perhaps a 10 acre lot. The big question is if you need fencing and barns already on the property or now.