Hi Jamie
There's a big difference between the Clyde Valley and the surrounding farmland. The valley itself is more of a gorge, so the old fruit farms down there were well protected from the winds that howl across Lanarkshire. Once you get up on the flat land, it's far more difficult for fruit to survive. It then becomes essential to take altitude into consideration. We are at 1,000 feet/300+metres. Up here, although we are still technically in Clydesdale, growing fruit trees is not easy. I am still experimenting (after 25 years) to find which trees will do the best here. Then in the valley itself you have to consider frost pockets (for veg too of course) and air frost, and sun. So, when looking at your proposed land there's a lot to bear in mind; you might find that a field in one place seems ideal, but 100m along the road the microclimate is totally different. These differences will be reflected in the price!
I suggest you pop in to Lawrie and Symingtons in Lanark and ask in the office what land they might have coming up for sale. A whole lot of land never makes it to the open market, as it will most likely be sold to the farm next door, after years of negotiation and haggling. So your best bet would be when a farm was coming up for sale on the open market, and being divided into lots. Find out all you can about land sales before you step in with a bid - you are likely to be disappointed many times before you get your land, unfortunately.
Good luck!