Based on the original poster's questions, I would ask
A) Do you now have an instrument rating?
B) What gear have you flown IFR with?

You can spend more $$ on electronics than on your airframe these days. If you leave space in the panel for nice boxes, you can start with just an audio panel and a comm radio and add later as your preferences for gear evolve.

Best of luck,

Wes
N78PS