I put Sylvania halogens in my '68 280SL and it was a noticable improvement at a cheap price. The lamps are readily available at any store with an auto parts department. However, My '89 BMW 325i has Hella lamps and the low beam light is much more effective. It's a four lamp car, so it isn't fair to compare the projector Hi-beams. Those are astonishing! If I knew I could get that kind of light out of the 7" Hella lamps for the Pagoda, I'd do it in a heartbeat. Might be worth the bit of extra money to try.
Let us know what you do.
Ray
'68 280SL 4-spd Coupe