Yes. You can stack stackable 440-G2 with any other stackable summit over any supported 10G interface. That include the direct attach cables.
There is a limitation that all devices must run the same version of firmware, and the cable must be supported.
There are 4 10G capable ports on The model you mentioned. Two of those ports can be used for stacking. No license is needed for stacking.
Regards..
Regards
Zdeněk Pala