Try the French Char 1bis.
It has the wrap-around tracks like WW1 tank. Tamiya do a nice kit in 1/35 scale, it will be a bit over 19cm long.
Otherwise there are several German and Soviet self-propelled guns which might do.
SU-152
SU-122 is also nice.
Stug III, Jagdpanther, Jagdtiger and Sturmtiger are suitable German vehicles. I won't post all the picks here-- check Wikipedia for self-propelled guns.
I think all of these are available in 1/35 scale and several are available in 1/48 scale.