Speaking of radio gear.... for Instrument Flying, and conventional VFR work for that matter, I carry a handheld and can hook it up to the external antennae via a BNC connector. Lots of people use ICOM brand, though I have found that I have more "bang for the buck" via my Sporty's SP-200, which gives me Comm and nav with VOR CDI "needle" capacity too. I haven't had to use it in flight yet, thank goodness, but it's nice to know it's there.
Just another two-cents worth I thought I'd toss in
I also carry a hand held Comm radio. Haven't used it in the air yet, but did use it on the ground once. Had a loose wire between my radio and the headphone jacks. Fortunately it manifested itself on the ground, I had to use the handheld to tell the tower I was canceling take-off and taxiing to my mechanics.
I bought my handheld back when I was flying the ultralight. Considered it my most important piece of safty equipment aside from the seat belt.
Phil