Hey PSPDemon check this out:
http://haloportable.forumup.co.uk
This Halo mod hasn't started much but they have a team built and started a few models. They are using the kurok engine.... I think MDave gave them the v0.4 as of now so they have skyboxes and everything. They are lacking a QC Coder and probably someone to help the modellers and textures in finishing the models and animating them.
I know you are most likely going to refuse this, and it's completely your choice, but maybe you can work with them to make a Halo Mod.
Once again it is completely your choice they just asked me to try and find a good QC Coder and stuff.
On topic: Did you start any maps yet?