HELP -designing new panel

I am new to IFR (pilot a long time just working on rating now, not sure how much I will use it but hope too).

I am restoring an old plane and doing a completely new panel, which I need to spec out in about 6 months.

I would like to keep the plane light, but still...

I need some help in deciding whether to get a 530 with a backup 430 - or something else. Maybe the 480 though I have seen the debates.

Perhaps a mx20 or Avidyne 500?

What about an HSI for the panel? sandel?

One thing I really do want is an active tcas and a display that i can instantly identify target location on.

I will also add a stec autopilot.

What would you put in? I don't have that much space. A 530 would fit in the center below the throttle quadrant, but any other nav/comm would go on the right side of the plane. In liu of a 530, I could put a mx20 like box in the center, but the nav/comm would need to be on the right side.

thanks for the help.