In the market for a Gen 2 ACE, but have some questions first

As the title suggests I want to get a Gen 2 Ace, but I wanted to pick your brains and get some opinions on what I should look for in buying the gun.

Firstly, which caliber should I go for? I already have a 5.56 gun and I don’t really want another one. Additionally, I have a 30 caliber suppressor that I want to be able to use on the gun (I’m aware I’ll need to get an adjustable piston). Between 7.62 and 5.45, which would be better?

Next, which barrel length do you think is best? I already have one 16 inch and one 8 inch rifle, so I was leaning towards 13 inches (plus the suppressor), but I was wondering if there was any drawbacks to 13 inches.

Finally, any galil specific attachments I should consider? I already noted the adjustable gas piston and optics and foreword grips are a given, but I was wondering about anything else that will take the rifle to the next level.

Thank you any and all for the guidance and tips!