As far as I know HB does not offer their standard M26 with steel track - only the later chevron track as seen in their M26A1 kit. Some of their T26E4 kits seem to have the steel track, but you'd need to look at the sprues to see if all the standard M26 parts come in the box. (Try https://www.1999.co.jp/ to see the sprues...)
They don't. The Hobby Boss T26E4 #1 vehicle has workable single link track, but the upper hull is not an M26, it is the T26E1 prototype hull with recessed grab handles on the engine deck. The turret also has the loader's ring-type cupola. You can build the first Super Pershing from the kit, and that's it. Or you can buy an RB Models 90mm M36 replacement gun barrel, leave off the counterweights, turret equilibrator spring assemblies and applique armor, and build the prototype T26E1 as it appeared in early 1944 (that hull and turret was reused for the first Super Pershing). The kit's serial number decal can be used.