My best suggestion would be to drive one, or even better, several, before buying anything.
Series Land Rovers aren't to everyones taste. And you will need to teach yourself to service and maintain the vehicle, unless you have a very deep pocket, and want to pay someone else to do it.
They can be reliable enough for a daily drive, but like all old vehicles they need constant attention. Daily basic checks, oil water and brake fluid, regular checks of transmission oils, steering boxes, etc. Usually plenty of bulb changes, propshaft greasing, odd track rod end, stuff like that.
Consider that most of a Series is 1930s tech with a few later improvements bolted on. The overall experience is more like a vintage car than a 21st century one.