wore-out-pilot - Welcome to the Pitts. I will try to add to what has already been said. Keep in mind that there are multiple ways to do things.

If you are using a gas engine you shouldn't have any problems with the CG. Just remember that the CG reference point is with the upper wing and not the lower wing. I used a DA-50 and if anything it was nearly tail heavy so I moved as much weight as far forward as possible. My ignition battery is mounted behind the fuse firewall under the fuel tank. My servo and smoke pump batteries are mounted behind the fuel tank just aft of the forward former to the wing saddle.

If you use a gas engine, the main mod you will want to consider is in reinforcing the firewall on the mounting box and also the mounting box to the fuse firewall. I pinned the firewall and then used tristock around the mounting box to the fuse firewall. I also added tristock inside the mounting box. Then I used fiberglass cloth with finish epoxy for resin. My firewall is good and tight with no signs of weakening. See attached pictures for more detail.

I added a simple smoke system on a smoke tray and then mounted inside the wing saddle area. I used a 24 oz smoke tank with a 24 oz fuel tank, but wish I had used a 20 oz. fuel tank with a 32 oz. smoke tank. The smoke oil runs dry pretty quickly, but the smoke is great while it last.

Mine weighs between 17-18 lbs which is a bit on the heavy side, but isn't a problem with the DA-50, which provides plenty of power. My set-up does not make for a 3-D machine, but I have ample power for my flying style. The only concern I have noticed about the weight is when a DS occurs. I have had three DS's, all of which were caused by me. I was lucky to get the Pitts down all three times with minor damage once. It flies like a rock without power. Weight is not your friend on this plane.

I also used a four servo configuration, but on my first Pitts I used two servos with a slave rod. In all honesty I don't see any difference in performance between the two or four servo set-up, but using four servos does require more power and adds more weight, but then you do have servo redundancy with four.

The most challenging assembly stage has to be in getting the upper wing aligned with the lower wing. You don't want more than 1 degree variance in the alignment from left to right or right to left as you look down from the top at both wings. Measure closely when mounting the Interplane struts and have someone hold the upper wing when making your marks to drill the holes in these struts.
Also, put your upper wing mounting screws into the Cabbane holes to join both halves together before tapping into the hard-points in the fuse. If you don't do this you will find that the upper wing Cabbane mounting holes won't align properly when inserting the screws.

Lastly, I used Robart hinge points after having the stock CA hinges fail in the rudder after four flights. I got the plane down without any problems, but upon further investigation i found that all of the CA hinges were brittle and tore easily. I have used CA hinges for years without any problems, but once I went to gas I had problems. I now only use Robart hinge points in all 1/4 scale, or larger airplanes, or any plane with a gas engine. You will hear different points of view on this, but using hinge points with Gorilla provides a better hinge and is as easy to mount as the CA hinges. If you must use CA hinges at least use the Blue Radio South hinges. Note - I added additional hinge points when doing this. Three is not enough IMHO.

Hope this helps. Good luck and post some pictures........ Note the tail wheel picture. Just a different approach that has worked well for me. Ohio Superstar medium sized tail wheel with a Rocket City Hardware Connector.