Thank you for considering a pit mix
I have been involved with bully breeds for the past twelve years from rescue to dogsitting.
Housing
First and foremost to consider before adopting a pit or pit mix is housing. Do you rent your townhome, or do you own your townhome? If you own, what does your homeowner’s insurance policy say in regards to pit bulls or pit mixes? Would you consider finding another homeowner’s insurance provider if they had breed restrictions? If you rent your townhome, what does your landlord say about pets? Breed restrictions? Renter’s insurance with a liability policy?
Actual Dog
For the most part, bully breeds are high energy dogs. Do you have the time and energy level to provide daily walks? Lengthy walks, hikes, or runs? Other enriching activities?
Bully breeds can also be Dog Aggressive. It’s considered a breed trait while in many other dogs it’s considered a breed flaw. This does not mean that all pit bulls or pit mixes are Dog Aggressive. Ours, for example, is not Dog Aggressive, but she is selective with who she likes. She LOVES our friend’s female German Shepherd, and she tolerates our other friend’s female Rhodesian mix. However, she barely (we don’t put her in these situations) tolerates female bully breeds. They should NEVER be people aggressive. It’s great that you said you would enlist the assistance of a trainer!
Pit bulls and pit mixes are relatively easy to care for although they are prone to skin allergies. They have short hair, and I consider them a “wash-and-wear” breed 
As far as temperament goes, they should be happy-go-lucky and goofy. They should LOVE people. I am sure the rescue that you choose (if you choose a pit bull or mix) will already have done temperament testing to ensure correct temperament and for better placement into appropriate homes. If not, I’d ask about it.
They can be stubborn with training, or at least people think its stubbornness. What it boils down to is that while one training method may not work for your pit bull, try another, and you’ll be amazed. Our girl is a whiz kid (often putting our German Shepherds to shame.)
Being a Bully Breed Owner
Bully breed owners need to have a tough skin and always remember that the public will always judge you. Therefore, it’s up to you to be a responsible pit bull / pit mix parent. Never let your dog be in situations in which it would cause a stir (unleashed, jumping around on people, mouthing people, etc.) Expect people to automatically judge you for owning a bully breed. It doesn’t matter if you’re a married, professional, white-collar job female living in Beverly Hills in the largest mansion on the block. Even some Veterinarians will judge you/your dog based on its breed.
Bully breed owners need to be aware of any BSL (Breed-Specific Legislation) in their area or attempting to be created in their area.
Summary
Bully breeds can be great dogs for responsible owners. They are loyal, humorous, and sensitive dogs. Be prepared for some judgment from others, but if you’re a responsible owner, you don’t have to worry about your dog causing any problems.