Some comments;

1) Crimping is very much the way to go. The heat of soldering (unless
you are very careful) can easily damage the dielectric insulator.
Invariably you are then left with a blob of solder that must be
wittled away to make thing fit. Ugh.
2) The less expensive sub-$50 (but not dirt cheap) crimpers seem to
work fine. Ratcheting type is highly recommended as they enforce the
correct amount of pressure. The $200 units are made to hold up to
repeated use over years, something most of us are unlikely to need.
3) Male/Female versus Two Males with coupler (whoa!) - Stick with the
fewest possible connections. Not only for the fact that there are
fewer things to go wrong but because each extra connection looses 2db
(rule of thumb) of your power.
4) While the boom is open, think about (if possible/practical/useful)
pulling extra air lines, coax, etc.
5) Test, test, test, test and test again before buttoning this up.
Get a professional to help out. Well worth the expense. Much better
now than later.
6) If you are on the scene of a boom break (I have), resisting with
all your might the temptation of cutting all the lines (air, coax) to
speed up the removal of the dead beast from the scene of the crime.
It is much better to try to take the time to disconnect things at the
cockpit end and pull them back so that any necessary splicing is done
in a easily accessible place.

Enjoy, John DeRosa