Will you be changing jobs when you move, or are you looking to buy close to where you are now?
I'm usually a big advocate for being debt-free, but there are times when debt makes sense. Never borrow money to finance a lifestyle you can't otherwise afford, but if the dividend on an investment will pay more than the cost of borrowing, it makes sense to borrow. If you're staying in the same area, it might make sense to borrow and buy as soon as you can, even if you live where you are for now, buying the land and moving to it after it is paid for has a number of advantages. One, you can use the time to clear land, build soil and get the perennials started and grow some of your own food. Two, frequent visits will let you get to know the land better. This will yield a better design. Three, it gives you a chance to see what you're getting into and how realistic your plans are before it gets too hard to back out of.
I know number three above is a double-edged sword and may let you give up sooner than you would if your food depended on your working more, but it's something to consider.
If you are only a couple of years away from buying land, you probably have enough of a downpayment that you should qualify for a decent interest rate and have a low payment.
When I took my PDC, I was forced to pay attention to things I had overlooked because I thought I didn't need them. Some of those things are what made things click to where I could see the bigger picture and not just a lot of pieces. To take a PDC, you have to do a design. My understanding is if you do a 2-week intensive, you do a design for where the class is. Most or all of the DIY courses expect you to do a design for where you are. If you do an on-line class and don't have access to a place to work with, I'm not sure what you'd do. Make sure you ask the teacher before you start. Other than that, I think you're be able to judge land better after taking th class, but that depends on how thoroughly you've studied on your own.