Well, they're both quite different. The things to think about would be:
How much exercise can you give a dog on your worst day? As in, when it's pissing it down and you have a streaming cold - how far would you be willing to go? Both breeds would need at least two hours a day, ideally spread out over two walks once fully grown.
Do you work? If so, what will you do with the dog? Four hours alone per day is the maximum most places recommend so can you afford to pay for daycare? Most charge at least £15/20 per day if not more.
If you have kids (I assume so as you say you want a family dog) what will you do with the dogs on holiday, or if you want a day out to say, a theme park or an attraction that doesn't allow dogs? Do you have someone who can have the dog or would you need to pay for daycare or kennels?
What grooming are you willing to do? Both breeds require brushing and trips to the grooming parlour to avoid knots and problems with their hair. This can be pretty expensive unless you're willing to learn how to do it at home.
Also, mess. Both breeds are mud and water magnets and will get your home covered in said mud and water! Short haired breeds are easier to care for (I can just wipe my beagle over and he's clean) and also don't require as much work when it comes to grooming and coat maintenance.
Cost - the bigger the dog, the more expensive they are. In terms of food, vet treatment (more medication = higher costs), insurance, and even things like grooming costs are higher the larger the dog.
Basically, how much time and money do you have to dedicate to your dog for the next 10-15 years?
I've recently become self-employed as a dog walker/sitter and I have a client who needs my services because she's injured her knee and her husband works away and she needs someone to walk her dog. Another lady needs overnight care as her husband is going into hospital hundreds of miles away. They're all things to consider - in other words, if you become unwell or injured or incapacitated in some way, can you still give your dog what they need (either yourself or by paying to outsource the care to someone else).
If I have a client who needs their dog walking five days per week, that costs them £200 per month, give or take. Daycare and overnight stays are even more expensive.