I used an Audiovalve Eklipse with an SA 100/3 to very good effect. I thought that the pair were very synergistic. The Eklipse is not rolled off, and has in fact some pretty impressive bass. While it may err on the darker, richer side of things, it is not "thick" or syrupy. And unlike alot of other tube preamps I'd auditioned, sounded smooth throughout the frequency range, without any midbass or midrange "humps" that I found distracting.
There's a pretty good write up in the most recent Hi-Fi+, if you can find it in your local bookstore.
Good luck, it's a real nice amp. I only got rid of mine because I needed to go smaller.