The CFII and MEI are nice resume bullets and would help you in the longer run. But you also need to consider what opportunities exist for MEI work in your area. At this point you DON'T need any more SE time.
Right now several regionals are hiring, and you may not want to miss the window, but if can get the MEI and then have plenty of students, you should probably do that.
A question about the Multi-block...is it solo time or does it involve a safety pilot sharing the time?
You could do safety pilot at your local airport yourself, just find a buddy...
Duchess $160/Hr / 2 pilots = $80/Hr X 80 hours = $6400
A few airlines are less than excited about safety pilot multi-time, but most don't care.
You could also see if a local FBO will rent you a twin at a reduced rate for 2 weeks to burn 80 hours. Since you'd be doing XC country stuff, not training they would save wear and tear on the aircraft.