Ok...so...I went to visit the first dog again, to get to know it a little better (it was the shelter lady's idea)...and...this is IM-FLIPPIN-POSSIBLE!!!!! I just don't know now!

He acted a lot different than he acted the other day!
Today he was less shy, a lot more friendly and affectionate, but also had a lot more energy, and was a bit jumpy.
She let me take him out side in the front yard area alone, with him on a leash. Let me tell ya, I got quite the dog slobber bath. I walked him around, and also sat down and played with him. He was all over me for affection, and rolling over on the ground wanting belly rubs and stuff.
So...I think it's time to start a list of pros and cons for each dog!
Zack
Pros:
Perfect size
doesn't seem to shed much
gets along with other dogs
seems to get along with cats
shows no signs of aggression
Friendly and affectionate
Young (1.5-2.5 years)
Allows me to mess with paws, tail, ears, and teeth
the shelter already microchipped him
Cons:
Can be a bit shy and fearful at first
is unknown around children
might have a slight barking problem (he's learning it from him pen-mates)
might be a bit more energetic than I originally thought
Notes on Zack: The shelter lady told me that while I'm on vacation, she's going to send Zack to a foster home..a lady with two children and other dogs. Zack will get a lot of socialization during this time, and maybe even get some training in.
Speckles
Pros:
Very calm temperment
not jumpy
seems to do well on the leash
doesn't really join in on the barking
is known to do well with children
does well with dogs
shows no signs of aggression
good size (slightly bigger than Zack)
Young (1-3 years)
seems to have some slight training already
Cons:
is unknown around cats (will have to test)
has a slightly longer, thicker coat, that sheds a lot
The shelter doesn't microchip, extra cost (probably not a huge deal)
...I'll add to these lists I remember things, or as I learn new things.