We’ve found that the dimensions on Hobbykings website are not the most accurate, and the real batteries are usually slightly smaller or larger. All batteries we recommend are ones that we have purchased and test fit ourselves, and can confirm fit fine with no interference or squishing. You should NEVER squeeze the body of a soft case lipo into a housing!
The 10Ah Turnigy lipo @corndog has linked above will absolutely fit, and is currently the highest capacity off the shelf 4s lipo we have found that fits.
We have not tested the graphene lipo @sigane17 has linked, it is borderline and may or may not fit depending on how accurate Hobbykings specs are in this case.