Yes, the Meng M3A3 kit will work for the M3A2. You’ll need it to get the M3 specific hatch unless you want to scratch one. The link below shows one I did. Not difficult, but why bother when you can just one from a kit now? You’ll obviously need to leave off certain parts, such as the IBAS and the DEV units, but also add others- In spite of what some folks have said it needs the shot trap armor, which is easily made from the base of an extra turret. I’ll even send you one for free. And while I am not going to offer so sell you my walk around from Iraq, I will send you photos of the shot trap area - better than what you’ll find from most photos on the net. You can replace the dog house with one from an old M2 kit.
As for the M2A2 ODS, yes, you can use the Tamiya kit, I would recommend the 3D printed update set by Jacques Duquette. I am building that exact vehicle because I found the MCD interesting. I know of no Bradley mount for it, but it’s easy enought to scratch build. For the base, I used brass shim rolled around a rod on one end.
I’m using the Meng kit, by the way - there are just too many things you have to fix on the Tamiya kit to get it where I want it, and while the Tamiya kit (or Academy) works, for me the Meng kit was the better option.
This talks about some of the things I did, and the reasons for my choice: