I've not dabbled with Bryce, but I've been looking for some SciFi ship models and Rj001's stuff looks great for my budget. But how do I go about texturing them? 

How you go about it is you Can either use a Bryce procedural texture or make one in Photoshop and import that texture into bryce you click the m on the object to open it and then you click p for a texture you want to import or you can make you own in the deep texture editor. Hope that helps oh and if you use mac you will need Bryce 6.3 or another version to import it and then import it into bryce 7 pro as the mac version has an annoying glitch that crashes when you try to import a picture. 

You can also use UV mapping in wings3D and save the model and import it in to Bryce.

Wings3D is excellent and completely free.

David Brinnen has a very good tutorial on how to do it here:

https://www.youtube.com/watch?v=Qi_QdTlRY6E&list=UUldbpx-WrHFHUD-w3IaIKkw

This was my first attempt following the tutorial.

http://www.renderosity.com/mod/gallery/index.php?image_id=2523372&user_id=472626&np&np