spa light

i need to replace my spa light.  The only info i have is that is a american products. The labe is half worn off and the only numbers i can read are 7810xx.  It is 100watts and the bulb says it is 120v.  I dont see a transformer so i am guessing it is not 12v.   What can i replace it with?  what about led?  do i need to do anything special to upgrade it or should i just stay with incandescent.  thanks for you help!