Unless your house has been specifically designed for art
display, using the 50-watt instead of the 35-watt bulbs will
help balance the light setting in the room and prevent
Artworks covered by glass will also benefit from the
stronger wattage bulb because the photons in the light will
penetrate the glass and illuminate the colors of the artwork.
There are more expensive bulbs available in a U V
inhibiting light. Essentially these bulbs put out very little
or almost no UV rays, and are good items to have.
Expensive artwork with constant exposure to bulbs, which
emit ultra violet radiation will fade and discolor.
Please make sure you hire a professional
electrician to do any electrical work in your house.
When you're looking for a good set-up at a low cost, my
suggestion is Gimble rings. This is not a technical term for
them, but these are rings with a light bulb suspended in the
middle, and the only contact made is between the small
socket hole and the bulb. They're not very fancy, but they
do a great job of lighting artwork. Gimble rings cut down on
excess heat and can be easily mounted to a track lighting
When you want to install track lighting fixtures for
your lights, the electrician will often cut you a break on price
if you buy the parts on your own. They'll provide you with a
list and this will save you some money as well. The track
manufacturer I recommend is Halo Track.  They are
inexpensive and easy to use. But I'm sure there are other
track manufactures out there equally good or better.
When you have your track lighting installed, arrange
for a dimmer to be attached. This way you can appreciate
the art through various levels of lighting.  You cannot
overstate the importance of having the right dimmer.