I have fixtures for track lighting that specify use of R30 or PAR30 bulbs. In similar fixtures (specifying R30) I have, in the past, used the new breed of spiral "flourescent" energy saver bulbs. Will these be acceptable in the track lights? Could I use normal household bulbs ("A19" type)? What is the difference? Also, the track itself seems to require "120vac 60hrz 20A" max. How many of the clip-in step cylinder lights can it handle? Thank You!

They will work OK but the light may not be what you are desiring. I personally use only PAR bulbs in track lights, and CFLs everywhere else.

And if your track is rated for 20 amps it can likely handle more bulbs than your circuit or wall switch!