Sump pumps are widely used where there is, or the risk of, getting water in the basement. Your home's location goes right to that point.
HOWEVER, it may not be as bad as you think (at the moment.) If I was you, I'd find out from your Municipality if you can find out where the 500 Year Flood Line is. This means that if your home is BELOW this line, there's a good chance you could be flooded out in less than 500 years, say ..., probably in 100 years. Bottom line, you may be in a Flood Zone.
1 year, 100 year, 500 year, or whatever-year, you may be in a flood zone. BUT, if your basement isn't to be a finished one, then you might not have too much to worry about (kinda). Jumping ahead, you need to talk to your Homeowner's Insurance Agent about what coverage you'd have and won't have where your home is. DON'T wait until you buy the house to find out you can't be covered for Damage to Personal Belongings, or something. Here in the states, Flood Insurance if bought from the Federal Gov't if you're in a Flood Plain. If you're NOT in a flood plain, but you get flooded, you have to talk to your Insurance Agent. That's why I'd do that now whether you're in the Plain, or not. It's quite possible that IF you aren't in a Flood Plain now, but later on as the result of a flood you were PUT into the FLood Plain, you'll be in a completely different situation.
Many people would LOVE to live in a home such as the one you describe for many, different reasons. At the same time, there are quite a few folks that wouldn't as well. So, in the long run, it's a personal call and perhaps a tough one. Perhaps others will have more to say. Here are a few links to read. DO read them in their entirety because it deals with the 'bigger picture'. SUmp pumps are fairly quiet. Since they're not meant to be on all the time, it's probably no problem. BUT, I don't know how much water you'll get down there even in a drought. If there are any EXISTING residents, try to talk to them to see what they're experiencing. That might help you decide.