IFR conditions can be extremely varied. You'll still need to avoid thunderstorms and known icing conditions in any RV. If you feel you'll need to fly in light ice then an RV isn't going to be for you.

As terms of the panel, there are companies out there that can cut a panel and make you a harness. You or someone you hire would only have to run the power wires. I personally love my panel setup, and find flying in IMC with it almost cheating. I came from hand-flying an analog 172 set up so it's night and day for me.