Lots of good advice on here. Won’t stop me adding my two penn’orth though 😉
Firstly, go down the rescue route, take their advice on what’ll be good with kids.
Secondly, go for a cross breed, less tendency to expensive, and distressing hereditary issues in later life.
Thirdly, if you want something to accompany you on long rides avoid greyhounds/lurchers. They are fantastic dogs but very fast twitch – they like to peg it around for 20mins then kip for 8 hours.
Fourthly, Staffies are great dogs, excellent with kids. Often owned by **** because they look scary.
My current is a lab/collie cross (Collador apparently) got from a rescue centre. She’s a lively, lovely dog. Food fixated so easy to train (though it means she thieves food when chance comes her way), very affectionate, good with kids. LOVES going biking and has pretty much worked out that getting in the way of the front wheel is a bad idea..
Fifthly, whatever you get its for life. He/she will repay you with unquestioning friendship and loyalty. Enjoy