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I would prefer to see you wait at least until your present dog is fully mature - 2 yrs or over.   Dogs of opposite gender often get along better, and if the older dog is very confident, it might be better to get a pup that is a middle of the pack type, not likely to constantly challenge the resident dog.  But, if you prefer males, it's often easier to get two males to get along than two females, so as long as you take your present dog's personality into consideration, it should be ok.  Be sure to get your pup from a very reputable breeder so that he can be returned on the off chance that your current dog does not accept him.  This is unlikely, as most adult dogs tolerate pups, but you wouldn't want to be stuck trying to rehome a byb dog if it should happen that there's a problem.
You can't choose the "ratio".  My feeling is that if they like each other and play a lot, that's a very good thing.  That will wane anyway as the pup gets older, but your current dog can help exercise the pup.  Pups that grow up playing with other dogs are less likely to nip and chew inappropriately, so your job is easier.  The one time you want them separated is for training.  Take the pup to class and at home, practice without his pal in the room.  Later, you can add distractions. 
It isn't a good idea to have two dogs of very similar status - they continually jockey for position.  So, if you have a submissive male, you could look for a bit more confident one.  Avoid bossy and pushy pups, but try to have a little difference between the two.

I really appreciate your reply! I definitely don't like dogs with a pushy/bossy personality. I actually had a Cocker with that personality and I did have to return him to the breeder. The Cocker was obsessive about constantly standing over/following Gingerbread around (and I mean stuck to him like glue). The poor guy couldn't get any peace without them being separated by a babygate almost all the time. Needless to say, I do NOT want that situation again.
 
Anyway, I'm going to take your advice and wait a year or so. I'm thinking that as Gingerbread gets older he's becoming more confident, I've noticed him carrying his tail higher, things like that, but he's still very laid back. So it would be good for me if HE is the more confident one.
 
Thank you again for some very good advice!!

I'm no proffesional but I know exactly how you feel. When my girl turned about 10 months I was heavily considering getting another pit for her. I ended not getting one and I'm so glad I did. She had her basic skills down but after they turn a year old things change. They have to constatnly be reminded and kept up on their skills, sometimes they even back track and start over. I also wanted her to really feel comfertable in her situation with me and so much bonding has happened since she has turned 1 year in January. They are still pups and I'm glad you decided to wait!

Luvntzus - I felt almost the same way as you.  JJ is near her HAPPY ONE BIRTHDAY next month.  For three months I had thoughts of getting a second dog.  I am trying to read as much as I could about having another puppy and stuff.  It wasn't until recently that I found out that the person I got JJ from had new puppies and that's when I got in touch with her.  I am on the waiting list as well but time will tell if I really decided to get a second dog or not. 

I know that my guy desperately needs a playmate at home, other than the cat, but I'm very concerned that he will revert back to "dumb puppy" status if I get one too early.  My plan right now is to wait until he's 2 before I start locating one.