If I choose to take jail time rather than probation, do I still have to have the interlock device in my car after my release. This is for my 2nd DWI?

It is likely but, unlike a third DUI, it is not mandatory.  They only thing I could find for a required interlock device and a second DUI was that it is necessary to install as a condition of release from jail on bond.  But this wouldn't apply in your situation if you are opting for jail time.

Bottom line, you might have to have one; depends on the judge.

At this point, you really should consult with an experienced DUI attorney in your area.  This is a highly technical area of the law and perhaps they can get the charge thrown out or at least reduced.