Its nice having the RMI and HSI however many of the IFR charter machines you will use have a fixed card ADF and a standard DG.
As much as using all the fruit for your rating is nice, I would suggest becoming proficient with the basic instruments first.
My motto is use the cheapest slowest multi engine aircraft you can, get the rating then go out and learn how to fly IFR in the real world. A MECIR is just like a bare CPL, it's a licence to learn and you are signed off when you are considered safe to do so.
Duchess, Partenavia or a twin commanche/seminole are a pretty good start.
I did mine in a Duchess when I had 1000 hours.