I'm not too sure about Dalmations - sure they look very cute with their spots, but they are pretty high maintenance - very energetic, can be quite silly and hyper, some are born deaf - which obviously is not good in a high maintenance, energetic hyper dog!! They are cancer-prone - usually skin cancer - so probably not that good in hot weather.
jack russels are pretty cute, but also can be quite hyper and energetic. and sometimes a little snappy.
labs and golden retrievers are good if you want a biggish dog, they usually last 12-15 years maximum. they are not cancer prone, but can have hip problems.
my favourites however are miniature schnauzers - i have 2 - and they are so cute. they are fine in hot weather - but they need to be clipped. they live a fairly long life, not particularly cancer prone. i'll try to get a photo of them and post the link.
i got that information from my mum - she's a vet - so if you want to pm me about anything - i can get some free veterinary advice for you!! lol.