Agree with this. Puppies are a ton of work, but there are a lot of great older dogs that need homes too. If you know a breed you want just google breed + rescue + city, or just hit some local shelters.
As far as travel goes, find either a good house sitter or a good kennel and the dog won't slow you down at all.
Bassett Hounds are good dogs; they have their noses in everything, and love to go hiking with you in the woods. For some reason they like to roll around in cow shit. They are much heavier/stronger than they look, but they still insist on being lap dogs.
I have a 4 yr old Black Lab and she's still extremely highper active. We were hoping that she would slow down as she got older but that didn't happen.
You need to pay attention to them quite a bit when you first get them to teach them right from wrong. They don't know not to eat your shoes or your shirt or your furniture. If you actually travel a lot, then having someone that can take care of your dog while your away is going to be absolutely a must.
Consider going to a dog shelter and adopting a dog that's already potty trained and has an energy level similar to yours.
If you like to go for runs everyday, don't get a bulldog because he won't make it to the end of the block and back, rather get a lab or a dog that likes to run. Vise versa...
Agreed on the older dog. You should pick one up in a shelter. It will be smarter, calmer, you can pick on that is trained, and you will likely be saving it's life after having been rejected by the last family who considered it undesirable once the puppy cuteness wore off.