Damn good suggestions from folks on "What I'd do if I could do it over again".

1.  I love my auto fuel transfer system.  I have a header tank and don't have
to think about anything except making sure on the checklist that the transfer
pumps work.
2.  I'm a big proponent of putting hydraulic pressure gages on the panel.
Monitor the up and down gear circuits.  Takes all the mystery out of gear
problems.  I think this is a 'must'.
3.  Put the seatbacks further rearward than you might initially guess.  Get
the inflight adjustable rudder pedals.  This way you don't have to keep asking
your passengers if they are over 6 feet tall ('cause they won't fit).
4.  You have to do something about canopy sealing (if you live in cold
climates).  I have yet to find an acceptable solution since the vacuum around
the rollover is enormous.
5.  I think I wish I went with the extended wing tips for better high altitude
performance.  In the midwest, sometimes high is good to get above the weather
(with oxygen) and our short wings poop out above 14k feet or so (depending on
loading).
6.  I like my wingtip mounted landing lights for the same reasons already
mentioned.
7.  Like others have said, get everything forward.  Under no circumstances
should you put the hydraulic pump behind the baggage bulkhead.  That's almost
as bad as permanently bonding your header tank deck to the fuselage (go with
piano hinge).
8.  Install an air/oil separator on the crankcase breather hose.
9.  Install the remote reservoir for the brake hydraulic fluid.  This is a
must.
9.  Get an AP with altitude hold.
10. I love my Bose ANR headsets.  This plane is loud.
11.  Think maintenance in everything you do during building.  How will you get
at something?  Will you require two people to remove a component because you
are too lazy to install anchor plates now?

Good Luck.
Ed de Chazal