"Better" is very broad. Most people in these lists would see the GPL as an advantage, but none would deny that Clang or LLVM are essentially free and compatible (maybe after some proofreading work) with the FSF's Free System Distribution Guidelines. As much as I prefer GCC and the GNU GPL in general, I wouldn't like to see precious efforts going to porting your OpenBSD spinoff back to GCC before actually making it a wholly free system. Not that I'm going to tell you how to spend your time, but getting a wholly free BSD is obviously the real issue here.
To be honest I like the idea of staying as close as possible to upstream OpenBSD while also meeting the FSF standards, so OpenBSD users feel attracted to make the jump. I think this was your original intention. If manpower is scarce, ask no more and keep Clang (assuming it doesn't need further liberation-wise tuning). There are some points that I would like to ask though, because your emails and website didn't clarify them for me:
How do we know beforehand that LibertyBSD is actually compliant with the FSDG? Why are you so confident that it will make it to the FSF list? Don't get me wrong, I don't underestimate your work and knowledge but I'm afraid that my donation might go to a dead end. I think going a bit more technical about what you are deblobbing and how you achieve it helps.
Assuming some trusted third party reviews your work and confirms it is libre, how will LibertyBSD be maintained? I look at all the work that Parabola hackers for instance undergo in order to clean up a GNU/Linux distro that is allegedly easy to clean, and I tell myself "Hell, this is though". Have you considered building a community? Some organisation like the FSF might want to help you complete the crowdfunding, but then what?