I'm starting my first column build. As this is my first build/still, my primary objective is to remain as flexible for future mods/changes as possible. As a result, I have decided to build my column to be "modular" based around a 3" diameter 54" tall copper column. The column is attached to a keg with a 2->3" adapter. I'll be using a 220v (4500w?) heating element (using my welder circuit in the garage) and controlling the power output with a 10kw SCR.
My first "head" will be a boka. I have a 6" ss spool on its way from China into which I will install the boka slant plates, take-off port (1/2" diameter) and thermometer port. This will mount to the top of the column with a tri-clamp. Above the boka spool, I will be installing a 12" ss spool for the reflux condenser (also already on its way). The water supply for the reflux condenser will be adjusted with a 1/2" gate valve. It will look something like this:
For the reflux condenser, I am undecided whether I want to use a DAD300-style CSST for the reflux condenser stuffed in the 12" spool or if I want to use the spool to build a shotgun condenser. I know that a 12" shotgun (as designed would contain eight 1/2" diameter vapor tubes) would be a massive overkill, but the shotgun could then be reused as a product condenser when running the column in other configurations (similar in knock-down to an 8' long 1/2" liebig). If I do decide to go with the shotgun, I've also toyed around with the idea of splitting the spool in half to create two halves within the single spool - effectively two 6" shotguns that can be run individually or could be run in parallel to have a 12" shotgun.
My second "head" that I will be building (after I get the boka head assembled and get comfortable with the general operation of the still) will be a vapor-infusion head so that I can make flavored neutrals and gin. I'll attach the reflux condenser (which would need to be a shotgun for this application) above the column connected to a 3" elbow connected to a 3" Tee which will house the infusion basket (would likely need an extension below the tee to gain enough length for the basket, but you get the idea) and either another shotgun or a decently sized liebig for the PC. I haven't included ALL of the details, but here is something to give you an idea of what I've got in mind:
With the components on-hand from the two heads above, I could easily add a gate valve to the mix and also run it as a VM still (or a LM/VM combo, or ???). Again - I'm looking for versatility so that I can play around with different styles and see what works best (for me) for producing different spirits.
I have installed the tri-clamp ferrules onto the 3" column (which required freezing the ferrules, heating the column and a little percussive persuasion) but haven't TIG'd them on yet. Here are a couple pics (don't judge - I know that I need to clean my garage!
) And yes - those are two fridges in the garage - one for cans/bottles and one for kegs. 
Before I have my buddy TIG them on (technically braze them on I suppose, but using a TIG torch for the heat source instead of oxygen/acetylene - the heat is MUCH more controllable that way), I wanted to make sure that I wasn't making a mistake (with the most expensive single piece of the build). Is a 54" column (100% of it packable) too long? Should I (gasp) cut it down a bit?