I was not aware of this version before, but our friends at Google have provided the following pics. Detail looks OK, if not a little soft. That said, still miles better than the old TUS version.
Playkid M60E3
TUS M60E3
ACE made one, I still have it kicking around somewhere.
I believe that the ACE version was not an M60E3, but rather the updated M60E4. One of the cool things about the ACE version though appears to be that you get additional handguards, flash hiders, and belt feeders so that you can easily change between the Mod 0 and the Mod 1.
ACE Mk43 - interchangeable between Mod 0 and Mod 1
I'm not up on all of the different versions of the M60, but Barrack Sergeant and Dragon made M60 variants that might interest you, as well.
BS Mk43 Mod 0 (aka: M60E4)
BS Mk43 Mod 1
IMHO, for the best M60E3 available to date, I would suggest the old DML version. This appears to be the best representation of the E3.
DML M60E3
This came with the older 'Kevin Yates' figure, a US SF Operator in Afghanistan, 2003. See below.
Note that I have not discussed any of the HT variants - all of these are either the original M60 or the modernized Mk43 variant. The same may be said for other M60s on the market - including those by Sideshow, DAM, ERTL, and others.