Something I've thought about, but have never had the opportunity to do, is to
use an H4 low/high beam in an auxiliary mounting position. Either 5 1/4" round
or the small rectangular lamp would work. Mounts could come from a motorcycle
supply shop or prolly JC Whitless.
Benefits - H4 lamps are relatively inexpensive, housings are cheap, and you'd
get additional switchable low/high beam from a single lamp.
Am I crazy (WRT this particular issue!)
1990 Audi 200T 60K
1988 Volvo 745T 107K