I don't see a version labeled 'trunk'. Which one should I select?
None that are listed inside the link you posted. Trunk is what is the latest devlopment version which can be found in the
svn tree.
That usually means you have to install version control for your system and check out the sources, then build lazarus from source. I would personally not advise to do so, seeing that you already seem to struggle with some of the more easier things in life (such as keeping your lazarus configuration from being send into oblivion
) .
An alternative to the requirement of svn (and working with it) is to download the latest sources
from ftp (*). I assume you are able to guess that Lazarus 1.7 means the latest from trunk
But, do check the date as this snapshot is not updated on a daily base, only when required (i will not bore you with the technical reasons of the what, why and when).
This does mean you have to compile lazarus yourself,
see also wiki (but skip the svn related parts).
Alternative link without svn stuff.
Also note
this is important, that you do not start your freshly compiled lazarus without taking precautions.
Your second lazarus should always use another configuration directory or it will most definitely screw up your existing lazarus configuration and could even cause your old lazarus to not start correctly.
Is there a trick to having two active Lazarus configurations on the same machine?
yes,
see wiki.
I believe I read that even though I am using a 64bit system, I should be running 32bit Lazarus. Correct?
It doesn't matter one bit which version you have installed and/or running except that you would have to install another additional package in order to be able to target the other windows platform. So that usually means that when you still produce a lot of 32 bit applications it is probably easier to install the 32 bit version so that you won't have to cross-compile. But that is from pure personal point of view.
(*) i am 100% done with correcting perfectly valid url's.