I was in your exact spot with that question a year and a half ago... and here's my advice....... do a TON of research and INTERACT with a few macs before you commit.
I have conures and a 1.5 year old macaw. BIG difference.
Macaws are louder, messier, a heck of a lot more DESTRUCTIVE, eat more, bite WAY harder, and need a lot more interaction and stimulation....*from personal experience*
But they are also crazy intelligent, jokesters, clowns, your shadow and best bud, and stubborn as mules lol.
I was caught between the GW and the B&G as well. I interacted with both and found, with my situation, a B&G was the best fit. They tend to be less intimidating, and less aggressive (from what I have seen). They are more laid back and forgiving. The B&G just seemed like the best fit for a first time macaw owner in my house.
But that will all depend on your situation. Keep in mind, your conures probably shouldn't be around the macaw because of the possibility of injury. So your time will be split a lot! Do you have that much free time?
Vacation? Renovations? Finding a place to board a larger bird is hard!! Trust me... I just went through that lol.
Toys...be prepared to spend a butt load on toys. Ir becau take a conure a few days to weeks to destroy that toy....a macaw can decimate a large block toy in an hour or less.
Mess....my 4 conures don't even create 1/4 of the mess my macaw does lol. Food, toy pieces, and pop everywhere lol.
Destruction... that break is NOT just for cracking nuts. My macaw tore a hole in my couch..in seconds. He pulled trim off the window. He chewed the top of my wood chair. He chewed through 4 perches..... and trust me when I say he has toys and foraging daily lol.
Bites....BITE PRESSURE TRAINING is a must!! It saved my butt a few times already. They can break a bone, rip chunks of skin, give you a new piercing. This isn't a conure bite. It can permanently damage you.
Noise....I can hear my macaw yelling 4 houses down.... with the window closed. Luckily my neighbors all know him and think he's funny
Cost... yeah.... start up? Bird, huge cage, big box of toys, food, vet check start up, perches.... about $5,500 USD. Monthly? About $100-200 in food(fresh and his pellet/seed). About $50-150 in toys as needed. And vet Bill's? Be ready to spend some serious money. Birds are more expensive to vet than a dog when needed.
Just be sure you know what you are getting into before you decide which one you want

they live a long time and are like a human toddler forever. It can be frustrating and aggravating....but can also be a beautiful friendship.
I vetted a lot of places before I chose my breeder, since my local rescue had strict rules which made my adopting from them hard. But luckily I had a friend who owned and raised the GW and B&G macaws, so I was able to interact with hers. Get GWs we're great until they are done with you... then they got nasty. The B&G would warn you afew times before you got bit. And overall they just seemed more my speed.
But I would reccomend this... find a rescue. They are always looking for help! Volunteer and get to know those types of birds. Hear the stories. Make friends with local bird communities and ask questions, try local bird fairs. Some will be happy to let you interact with their birds.
My macaw, Rhage, is my world. He's messy, bratty, and loud... ...but he's my shadow and a total clown. He loves to play and walk with me. He talks! He always feels the need to be on me in some way.
Macaws in a word? Amazing.
But if not given what they need? Nightmares.
Just do your research. Find a way to actually interact with both. Contact a local rescue. Do exactly what you are doing right now... asking questions
These guys are 60+ years of fun, crazy, and commitment. Be sure you can hang on for the ride

it can be bumpy aaaannndddd breathtaking.