Dont panic, you are only 6 weeks pregnant which is great because at least you have a bit of time to implement some changes well BEFORE the baby comes! This will hopefully mean that the dogs will be used to the changes by the time the baby arrives and wont learn to resent the baby. (you will have much less time for training with a new baby on your hands, so do it now!!).
It would be best to make the rules the same for both dogs (irrelevant about one being well behaved), simply because it will be quicker and easier to enforce and easier for them to understand.
Also remember that the chewing will hopefully be lessening now that your dog is 2 years, but always make sure you still give them plenty of things to chew and that they know what they are AND are not allowed. My dog is simply not allowed to touch anything that isnt hers and i did not give her.
If you have a room that will be the babys nursery... start practicing NOW that the dogs are not to enter that particular room. It wont hurt them to have one place in the house that is out of bounds... there will be times where your baby may be on the floor (for dressing etc) and you dont want the dogs in there leaping all over the place. Also you dont want them sniffing through your nappy bin or chewing the babys toys and things. Practice going in the room sitting down and sending the dogs out - take a magazine and have a read in the chair you will be using for nursing etc and teach them, that the room is out of bounds.
As my house is smallish with lots of breakables - i do not allow really rowdy behaviour inside, and with a baby coming soon, you may want to start that training too. But make sure you take them out and give them plenty of other exercise and stimulation, as it is not fair to just expect them to be quiet and still all the time. (running around the backyard so to speak is not enough for any dog, especially a 2yo boxer, so make sure you are doing lots with them).
Crate training is also excellent and gives your dog a quiet spot to settle. And it doesnt matter if your dogs have never used a crate, old dogs can learn new tricks!! Practice leaving them in there for short periods of time at first and once they calm down they can come out -not before! (they may carry on at first but ignore that behaviour until they settle). Make it a nice place for them to go, a chew treat and cuddly blankets etc. Then down the track, if they get barky or silly you can just place them calmly in the crate and leave them to settle. Be careful not to use it soley as punishment. Use this time to train them to "enjoy" their crate. (they will hate it at first, but dont give in). Eventually it will become their little haven to get away from things.
It is unfortunate that they have already learnt to jump on your sofas and bed. If you decide to change this rule their must be no turning back! You cant expect them to "sometimes be allowed and sometimes not" that will cause confusion. But they can learn, just be VERY consistant and dont ever weaken thinking "oh just this once". Vigilance and consistance are the keys. Again teach this NOW so that the dogs do not associate the changes with the arrival of the baby in 7-8 months. My dogs are most definitely not allowed on any furniture and thats where the crate training is great... THEIR space.
Perhaps you should also do some obedience work with them now, so as things progess you have someone/trainer who can help you along the way. Good luck! And when your baby comes home, you will need to still spend time and energy with your dogs to avoid jealousy (it does happen).
Lastly, try to get your dogs to meet and learn to get used to kids starting now! Slightly older kids that you know will be gentle and calm to start with. Little kids can be a bit noisy and rough, but the sooner you start teaching them to deal with it the better it will be for you dogs and your baby (it will be a couple of years before your baby is interacting with your dogs much (toddler age), so start now and your dogs will hopefully learn to cope with kids (some never do). Introduce them gradually and ALWAYS with strict supervision and watch carefully for signs that the dog is not coping. I used to get my nieces and nephews (ages 4 -12) to make them sit and feed treats etc. so the dogs have to learn to be patient AND that kids can be a good thing... food.