I don't really know much about frame geometry or gearing, but I can tell you that I have the Redline Conquest Pro and I love it! My road bike is a Giant, size small, and my Redline is a 48. I went with the Pro because it has 10-speed gearing, which all of our other bikes have as well. I wanted to the flexibility of being able to swap wheels with my husband, if necessary.
I have a single ring up front, a 38, which I switched to when I found that my 42 was too big and didn't give me enough to get up some hills. But, I'm not a real competitive rider and am not in racing shape. You may find you need something different. I do, however, highly recommend the single ring up front. I can't tell you how many people I have watched pull over to the side in the middle of a race to deal with their chain coming off. I've never had that problem.
I bought my bike from someone who is very experienced in Cross and he was extremely helpful. I would recommend checking around with others in the area who are experienced cross racers to see what they recommend. The more experienced cross folks tend to ride expensive wheels, I think, but as a beginner I would never think to do that. I've crashed way too many times.
I'm sure you'll get some other great opinions from the ladies here, too!
Good luck!