Given the rapid advancements in Experimental avionics technology, if I were looking to buy an airplane today, I would likely prefer one that had the barest minimum VFR panel.
Why? Because by starting with almost nothing, one can install a beautifully-integrated IFR-capable set of avionics without having to worry about how to adapt to existing, perhaps somewhat stale avionics.
Why #2? Because I started with a very good but outdated VFR panel. Had I not had that existing investment in wiring etc, I would have started out with a fresh panel and been done much sooner with far less hassle. Trying to build on something that's existing, particularly if poorly documented, can often take more work than ripping it all out and starting from scratch. Particularly so if the original build quality in the panel was not the very best.
Spend your money on a good, solid airframe. You can add interior, paint and avionics as money becomes available. Get the airframe configuration you want (A-model, slider or tipper as you prefer) and the engine/prop combination you want. Everything else is just window dressing that can be changed relatively easily down the road.
WRT autopilots, if you are looking at going with an EFIS, Garmin, Dynon, AFS, GRT and MGL all have good EFIS-controlled autopilots. You'll have to install two servos to get the functionality you want so there's not a huge difference in installation complexity between brands. Same goes if you want a stand-alone A/P; TruTrak and Trio are excellent. TruTrak integrates well with the GRT EFIS offering (or you can use GRT's built-in auto-pilot of you select their EFIS product.)
It truly is amazing to see the level of functionality we have available to us in our homebuilt airplanes. Those who own certificated aircraft are green with envy!