Hi Rob,
Although the Berringer wheels may seem like a lot, when you are supposed to re-pack your wheel bearings every annual like many do, you will think all of a sudden that seal bearings at the outset were cheap. This is particularly true if you will be operating off wet/grass runways. I used to curse shimano wheel bearings on bicycles and since changing to sealed bearings I've never had a failure. As an alternative, Antisplat Aero does an upgrade to the stock wheels for cartridge bearings. Fundamentally the Matco brakes are Ok (apart from needing the external spring upgrade on the master cylinders and the single bolt for the pedal pivot point).
http://www.vansairforce.com/community/showthread.php?t=40235&page=3
https://antisplataero.com/products/main-wheel-bearing-mod
If you are operating off a grass airfield, I would look at getting an alternative tailwheel, as the stock version is essentially an arrestor hook should it go down a rabbit hole. I think mine is a flyboy accessory version. I also got the Rocket Link, but haven't used it as I'm a low time tailwheel pilot and the Van's factory pilot recommended the use of chains for now. None of the tailwheels available on the market today are perfect however, as I am convinced they need a grease nipple/zerk on the rear of them to keep the bearing and locking pin positively pressurized with grease. If I don't disassemble/clean mine every 25hrs, the pin ends up getting stuck and not engaging/disengaging properly.
Re the tip-up/slider deal, the Supertracks system has given the slider a distinct advantage in my mind. It's super simple solution makes the ease of access to the baggage compartment a breeze. I've carried a number of items lately, like large solar inverters and mountain bikes that I would have had no chance of fitting in the tip-up. I landed three days ago and it was 34?C on the ground, so being able to open the slider immediately was an absolute savior. That same flight started out with me escaping a thunderstorm on an island. It had just started raining when I got in the aircraft and the thought of tipping water down the back of the instrument panel as I entered the aircraft is troubling to say the least.
http://www.vansairforce.com/community/showthread.php?t=100424
Other items to think about sooner than later would be firewall/belly ceramic/stainless/titanium fire insulation, conduit for under the baggage area or down the aft of the fuselage to make wire installations easier, type and routing of static air system, autopilot servo mounts, where you are going to put your fuel filters etc.
Good luck.
Tom. RV-7