First of all, the rankings of M1A1 tank kits in 1/35 scale go thus:
1. Trumpeter M1A1 (various versions with & without mine plow or roller)
2. DML M1A1 (various versions with crew/interior, mine plow, USMC)
3. Tamiya M1A1 (with and without mine plow)
4. Academy M1A1 (poor Tamiya copy)
5. Esci M1A1 (OOP and we're happy that it's gone)
One problem with the Academy tracks is that the center guides are in the middle of the track pad instead of straddling two adjacent pads (tracks are the early type that started getting phased out in 1989-90, but still can be found). Eduard does a photo etch set specifically for the Academy kit (35057), replace the tracks with the AFV Club ones. Verlinden made an interior for the kit (#621) too, but it is OOP.
Model Point has just come out with a new 120mm gun tube. I have not seen it, but word is that it is nicely done. DML makes a set of M1A1 tank crewmen (3520). It is the same crew that comes with one of their M1A1 kits.
As far as gear, there are several modern accessory sets by various manufacturers that will work with the kit.