I wear a bowtie occassionally myself (even though SWMBO hates it). I don't think you need to worry about bucking the conservative trend in your firm. After all, Virginia courts are about as conservative as it can get and nothing is more classically Virginian than a seersucker suit with a bowtie.

If you're looking for an inexpensive way to dip a toe in the water, try www.thetiebar.com. You can pick up some very nice silk bowties for $15 there...