Re: Wanting to get a dog
I'd worry about an older dog if you will be immediately "abandoning" it (going to work, but not to a dog) within days of adoption. Such a scenario could easily trigger undesired behavior and really hurt the bonding process if the dog has an abandoned or abusive background.
Any new animal should be caged while you're not home until you get a handle on their behavior and reaction to the new digs. Otherwise the poor guy might not understand marking every room multiple times is unnecessary- it's his already, no pee needed.
Puppies are work, but they're trainable. A puppy would probably also be less affected by your absence in the long run.
Assess your lifestyle honestly- are you truly active or do you actually get out in nature 1 time a month. Ask friends and family what sort of dog they see you with. If a particular breed keeps getting mentioned, look into the breed. Does the breed fit your lifestyle and ability to interact with the dog? Does the climate suit the dog? etc. No matter what, the dog, if not psycho, will not give a crap about most anything other than how you treat him. It's up to you to decide what sort of dog you can be the best owner to.
I'd personally love to have an Aussie Cattle Dog. But they're not a studio apt dog. So, I'll wait until I am in a situation I can have one and it be a proper environment for them.
Just my 2 cents.