Hello
There will be other components involved to patch when you update the SAP_BASIS as there are dependencies involved (eg: SAP_APPL, etc). If you are using MOPZ to create a stack file then MOPZ will take care of the dependencies involved. SUM basically uses SPAM/SAINT to patch but will also provide you few options to choose different update strategies like downtime minimized with the help of a shadow system. You also have the option to patch the main system without a shadow. As you have a dual stack system SUM will let you handle both the updates in a console. You will have two tabs, one for ABAP and one for Java. I was able to use JSPM on a Netweaver 7.0 based system but if you are unable to use JSPM as mentioned by Yves and if it is suggesting you to use SUM when you launch it then it is better to use SUM for both.
Regards
RB