I've had a Golden Retriever and a Newfoundland. Both require daily brushing but the Newfoundland takes much, much longer, and you never finish! Goldens can probably avoid the groomers costs, Newfoundlands not so much. Redecorating is a regular occurrence with Newfoundlands, purely because they shake when wet. It goes up the walls. Mine doesn't slobber indoors, only on walks.
Training wise, Goldens are easier as don't have the stubborn steak of a Newfie.
Exercise wise - big difference - Goldens are much more excitable therefore need more stimulation to drain the energy, Newfies are calm (ish) after about 2yrs. It's all individual though, albeit the breed DNA gives the 'breed traits', each dog has its own personality.
Both breeds will knock toddlers flying; both breeds are known to be wonderful with children, but as an ADULT regarding boulishness, never aggression. Not enough information is given on the 'child friendly breeds' who are bombproof once mature around kids, but like bowling balls when kids are little.
No vacuum gets rid of Newfie hair (I have 3 top brands and the best is the dogs' slicker brush).
Both need human company and to be part of the family at least 80% of their lives. ALL of the family have to be consistent with training, including children.
Before getting my Newfie, Bernese was a breed I studied and researched. Unfortunately they have a genetic cancer gene which means they rarely live beyond 8/9yrs-personally I couldn't cope with that. Giant breeds tend to live shorter lives but Newfs and Goldens (not classed as a giant breed) seem to do well in that respect.
Enquire through breed clubs as to whom is a well respected breeder. And don't pay a penny for a breeder who does not health test both mum and dad for hips, elbows and ALL genetic problems for that breed (inform yourself beforehand).
Lastly, stay away from internet sellers and especially Pets4Homes. Too many puppy farmers on there who can convincingly convey a 'family approach' to their litter and how it's brought up.
www.champdogs.co.uk/?classic_site=1
is a good website for choosing breeders who health test.
Hard choice but wishing you all the best with your new pup!