Mun Base Landing?

[Kerbodyne S3-14400 Tank]

So, Iv'e been trying to land this weird base thing on the Mun. It's pretty confusing for me to explain so I just made a graphic.

http://imgur.com/a/lY6fK

The problem I'm having is landing it. If I keep it angle at "Normal" It does pretty good, I only have to make small adjustments to tilt. But, as soon as I get below Lunar orbit, "Normal" changes to a different position entirely, and my RCS system turns my rocket at an angle that I can't land at. I would turn off RCS entirely, but then my base would just start flipping out uncontrollably. I would appreciate it if anybody had any advice on how to make a controlled sideways landing. (I have Mech-Jeb tier two, if necessary.) 

[Streetwind]

Welcome to the forums!

When your navball switches into surface mode, the Normal/Antinormal and Radial-In/Radial-Out markers disappear. The entire frame of reference is reoriented towards the ground. You can anticipate this, and manually switch back to orbit mode, but that may make landing difficult because speed is counted a different way. Instead, try some of the other orientation options. I assume prograde/retrograde won't help you, since your command module is inline, but try one of the radial directions.

[Aegolius13]

It might work to put a docking port or something on the center, facing upward.  Then you can use "control from here" and land it like a regular lander.