Thanks.
By the way, I've found that just toying around in radiant doesn't work well for this kind of map/ceiling. Here's how this became easy and fun for me:
1. First, find some pictures of architecture that you want to emulate. No need for anything spectacular, but it really helps to browse through google images for words like "medieval ceiling" or "support column" or the like. I save pictures that I like to a reference directory and look at it a few time before deciding on what to make.
2. After selecting the look/general shape of the bit I'm going to make next, I make (very rough) sketches -- just real pencil on paper. Some may not have suspected this, but I'm actually very bad at doing real drawings (they're messy and it takes many tries to get lines to come out right). But the point is to get a rough idea of how the bit looks. I usually do two angles to make sure I understand what I'm picturing. That way, you know that you're going to make something that can really exist in 3D. :]
3. Next step is not much different, but I make same additional sketches or add some lines to previously made sketches, while thinking out the brushwork. It's usually not too hard to decide what needs to be done with curve patches or brushes. It may take some time to figure out what details to make with brushes, or use textures for them.
4. After all that, I do the real work. Sometimes I test out some of the thought out shapes first, but usually having worked it out before helped to smooth out the process. I usually use placeholder textures that show at least the right kind of contrast and texture detail to let you see how the shapes work.
Planning how rooms interconnect without breaking up the shape of ceilings is difficult, and you can see that I'm not entirely good at dealing with that kind of thing. But it helps if you can accept moving entire rooms around to make the brushes within other rooms work..
5. Not a really the fifth step, but usually mixed in during the fourth: I make my own textures. I use cgtextures.com, which is an amazing repository -- very much worth an account. They have tiling textures aswell, so that should help you if you're not too keen on doing a lot of photoshopping. Pretty much all textures in tabq1dm5 are based off of cgtextures material.
By the way, if you need anything edited for a specific idea, don't hesitate to ask - I may even have something lying around that could help you out. The biggest obstacle to devoting time to making nice architecture is not having good textures to make it all worth the effort.
By the way, I've been meaning to link you up with this:
I found that the older version was a bit too bright for my map. Looks like that goes for yours aswell, so this one may look better.
By the way 2, what door texture are you using? I'm considering making a fresh door texture to match the look of my map. Not quite sure how much I want it to match the original Quake door.. would be hard to pull off and still be consistent with the quality of the surrounding textures..