i think you can just tap into another vacuum source and keep your econ guage if you want.
also i agree with michael, i've had over wattage bulbs withseemingly no problems. i may have been lucky.
with the +50 bulbs available i feel more comfortable with them.
try the philips or osram silverstars from www.powerbulbs.com
they have free shipping worldwide.
i recently bought the "blue vision" city light bulbs.
give them a try.
you can easily buy 4 bulbs [2 pairs] h4's, 2 h3's, and new blue vision city light bulbs for what those piaa ones would cost for a pair of h4's.
just a thought