Acts like a wookie when sitting to get leashed

Howdy all, had a question regarding some behaviour that's gotten out of hand lately with my GSD/Chow mix Peaches. When I'm prepping them both (have an E. Pointer - Simon) for walking, I ask them to sit, and about that time Peaches starts making a TON of racket and crouching/darting away like we're playing a game. Problem is, she used to just make a low sort of whine that's now escalated to flat out growling, barking and snarling, all the while her tail's going a mile a minute. I've tried to ignore her until she stops, but the moment I bend back down, she's at it again. I've tried walking away and coming back, leashing her away from the door, but it's the same each place. I flat out refuse to try anything more aggressive than that since both she and Simon are rescue dogs that were badly abused by previous "owners" :( Any suggestions?

Okie dokie - here you go. First you need to work on relationship (our first 3 drills) but beyond that you use 2 leashes. Have the dog on a leash and then ask for a sit and when she is calm you put on the 2nd leash and take off the first. The first leash empowers your word, because you can correct her bad choices - always giving her another chance to make a good choice. Do this several times throughout the day. Have this dog on the leash with you in the house as much as you can stand it. This puts you in the leadership role and makes her the follower. Ask her to do lots of things throughout the day aswell. Makes you the teacher and her the student. don't be shy to give her a correction for outrageous behavior just be sure to balance it with good soft praise when she does the right thing.
Please don't mistake good manners for cruetly. Just because she had a rough start doesn't mean you can never say 'no' to her again. You have to gage your reactions to her by her sensitivity and responses to you. Don't intimitdate but don't get blown off either. There is balance in all things.

Do you know the cause of the behaviour? Does she not want to be leashed walked and is upset? Or does she want to play and is excited about going for a walk?

Noise and high energy generally means a high emotion, but I don't know which one from your post, and each is approached with a different solution.

Thanks tenderfoot, I'll give the 2 leashes and leashing through the house a shot. I've had these guys for over 2 years now, and she didn't start out this way. She's so excited and happy to be going out, but she's gotten a LOT more exuberant in the past 4 months and we've moved in that time frame (which has to be stressful, I know it was for me). I've been extremely careful with their training, her's especially, by using firm voice commands and a lot of 1:1 work, and major treats, which have brought her from being Cujo when we're out walking to sitting quickly and looking right to me when another dog comes within 30 feet (working on closer ranges very carefully). Could it be displaced separation anxiety on her part that she's just so wired to be going out she's pretending to be Chewbacca?