After going through a dozen or so H7 bulbs in a year (2002 XG350), I bought
a cheep HID kit off Ebay for around $50 from Hong Kong.  It involves HID
bulbs and a pair of ballasts.  The HID bulbs have no filament, so they are
much tougher than the regular bulbs.  And the light output is fantastic.
They install  pretty easy, and you should be able to install things so, in
case of failure, the ballasts can unplug and the old bulbs can go back in.
I did have some problems with mine: everything worked great for about a week
and then one of the ballasts shorted, taking the headlight fuse with it (no
headlights).  Removing the bad ballast, putting a normal bulb back in, and
replacing a fuse got the headlights working again.  I was able to get a
replacement ballast in a month or so (the hardest part was finding out who
to contact).  Its been a year since the replacement ballast went in, and I
have not had any problems with them.  If anything fails in the future, I
will just buy another set as they are dirt cheep for a HID system.  I bought
the 5000k color and I think its great.  Most of my driving is city and mine
are installed on the low beam headlights.  You might want to consider doing
the high beam headlights?

Dan