How big do they get? the ones on the pics on this forum seems to be small but apparently they get like 12 inch long including the tail?
I'm awful at estimating but they're about the size of a small
guinea pig or rat. Females are smaller then males and more slim and rat-like, from what I've seen (I have three girls).
What are the personality like? Rabbits? rats?
Neither, degus are unique animals

. They bond very, very closely to their caretaker and are extremely friendly, playful, and energetic. However, they are not cuddly and most don't like being held...they'd rather ride on your shoulder or sit in your hands. Degus are also more intelligent then alot of small animals which means they also get into alot of trouble!

Keep in mind that it can take a while to form a bond with a degu...if you grab at them or force them out of their cage they won't trust you. Patience is the key

.
Do they get along with rabbits (i have two)
I've heard of degus being friends with rabbits, but I personally keep my degus and bunnies seperate. And if you mean about housing them together, definately not (though I'm sure you know that).
Are you thinking of getting a pair?
I don't live in Florida, but average price for a degu seems to be between $20 and $40 depending on where you get them. But I was lucky and got all of mine for under $10 each

. Of course, part of it is that the petstore manager knows me personally, haha.