IM 141 or IM3 choice (and how to get IM3 latest test build)

This is a replacement for my previous post which wasn't at all explanatory enough.
The website I'm administering is running IM Portal and PHPBB 2.0.X. I've been working an IM141 deployment for it, but got delayed by other factors in life (like work). Someone else is starting to work the site as well and is strongly advocating going to PHPBB 3.0.X ASAP and working the rest of the integration stuff later. That means losing alot of existing extra content beyond the boards.
Going to PHPBB 3.0.X and retaining the extra stuff means going to Stargate Portal which has always been the plan, but I've become attached to some of the IM141 mods and was waiting for the IM3 deployment, but waiting isn't an option.
So my questions are:
(1) Is IM141 (patched per IM141 22 to 23 patch) as secure as IM3 even in it's latest test build configuration?
(2) If I wanted to participate in the testing of IM3 - how can I find everything I'd need to build a test site up to the latest config? I've tried browsing the forums and haven't found enough data (or anything past June).
(3) Should I just bite the bullet and go to PHPBB 3.0.X and Stargate Portal 1.0.3 and hold off on the other mods (or incorporate them singly by hand)?
I'd appreciate any advice or information. You can respond by PM and delete this post. You can also reach me at my email address on the board. I just need some ammunition to make the other newer administrator happy.
The website I'm administering is running IM Portal and PHPBB 2.0.X. I've been working an IM141 deployment for it, but got delayed by other factors in life (like work). Someone else is starting to work the site as well and is strongly advocating going to PHPBB 3.0.X ASAP and working the rest of the integration stuff later. That means losing alot of existing extra content beyond the boards.
Going to PHPBB 3.0.X and retaining the extra stuff means going to Stargate Portal which has always been the plan, but I've become attached to some of the IM141 mods and was waiting for the IM3 deployment, but waiting isn't an option.
So my questions are:
(1) Is IM141 (patched per IM141 22 to 23 patch) as secure as IM3 even in it's latest test build configuration?
(2) If I wanted to participate in the testing of IM3 - how can I find everything I'd need to build a test site up to the latest config? I've tried browsing the forums and haven't found enough data (or anything past June).
(3) Should I just bite the bullet and go to PHPBB 3.0.X and Stargate Portal 1.0.3 and hold off on the other mods (or incorporate them singly by hand)?
I'd appreciate any advice or information. You can respond by PM and delete this post. You can also reach me at my email address on the board. I just need some ammunition to make the other newer administrator happy.