In all honesty, most classic automatics are easier to maintain than modern ones, as the majority use a straightforward torque converter transmission. The downside is that they're generally far less fuel efficient. Without knowing your budget or the size of car you're interested in, it's hard to make any recommendations, but something with a low-revving, large engine such as an old Jaguar or a Mercedes-Benz saloon would be a fine choice, or perhaps a classic Range Rover? If you're after a smaller car then you won't find many automatic sports cars, but when it comes to cheaper, mainstream models automatics often outnumber manuals in terms of survivors, as they generally attracted older, lower mileage drivers when new and are more likely to have survived. Once you know what type of classic you'd like, the best bet would be to approach the owners' club or look for relevant social media groups online and ask people who know the model about the reliability of automatic variants.

Good luck,

Craig