First, buy your son light-weight used tools so he doesn't steal yours (speaking from experience here - toy tools were never good enough). We love the Brown-E too.
I'm guessing with your background you might better know how many acres you might need to support the animals you may want. Then add on orchard, garden and forest land. If you choose to heat with wood, you'll need to find out the wood most prevalent in that area and estimate amount you'll need each year (depends on stove, weather, house size) - then determine how many acres can sustain taking wood annually (calculators online for this)...unless you plan to get wood elsewhere. Look at soil type - what it was used for previously and what you want to do with it to see if they align or if you can build the soil back up. Aspect - planting on north or south side, etc. Slope - flat useful land or rugged terrain. Ignoring the animal possibility, you will likely need less land than you think. You can plant densely. Lots of land = lots of work. Smaller plot = less need for larger (more expensive) tractors, etc, less fencing, less management. Generally can equal less cost as well. Of course, if you want privacy you might want more land. Water - well, pond, rivers. Water is useful and soothing. It was one of the mandatory items on our list. Check into water rights and if you need them for what you want to do. There are often exemptions for personal use but depending upon how many acres you irrigate or animals you want to water, you may need water rights. Some places they come with property and others they don't.
Hope it goes well for you!