Thinking about getting a new dog, any suggestions?

You do not say much about your living circumstances, and that does make a lot of difference in deciding what kind of dog to buy.
If you live in a house with a yard, where a large dog can go outside a lot to romp and play, then being inside and outside would work. Even if you are able to take the dog for long walks every day, it would probably work out okay. A large dog just needs room to run around, more than a small dog does.

If you live in apartment and do not have a good area to walk a dog, or let them run and play, then you might want to consider getting a smaller dog instead.
Some smaller dogs will be excellent guard dogs, even though they can't do as much damage to an intruder as a large dog might do.
If you live somewhere that you fear someone actually breakinginto your house and hurting you, then a large dog might be necessary, even if you have to make modifications in order for him to be exercised.
If, however, you just need a dog to alert you and bark, then a smaller dog would be fine for that, and they are usually very alert.
Tootsie, our Blue Heeler mix, is a great watch dog, and is also very friendly. Plus, at around 12 lbs, she is not overly large to have in the house.