Vtin,
CAT, Lamm, Emotive, Hovland, Joule, are all good choices, I've owned all but the Hovland. You don't balanced preamps to use with Rowland amps to get their maximum benefit; the Rowlands use Jensen transformers whether the XLR or RCA inputs are used. And frankly, I generally find that single-ended RCA sounds better than balanced XLR the majority of the time.
Of the pres I mention above, the Emotive is the best deal (i.e., cheapest) and doesn't give much if anything away to the others in terms of sonics. It is excellent. But if you do phono too, it's awfully hard to beat a CAT....