That's an odd configuration - quite long, tall and skinny. I don't think you'll find too many pre-made routers that look like that - as you've noticed, they are usually built for people who want to cut sheet goods. It's proportioned more like a vertical mill, although the 5-foot span is longer than the X axis travel of all but the larger models. Are you planning to add a 4th axis? I've seen guys making pool cues put together machines like that with a rotary table. If you don't want to buy a machine that's wider than you need and modify it, you're probably going to have to build it yourself. But that shouldn't be too hard - especially since you've already got the Taig to help you produce all the motor mounting plates you're going to need. Feel free to put together a sketch design and post it here - there's lots of help available if you ask.