Well it's possible. You can use your computer and a free hosting program called Karafun from
www.karafun.com with the home subscription of $ about $10 per month gives you access to 20K+ songs via streaming so internet will be required.
Home stereo bad idea - more often than not people end up blowing their speakers since they are really not designed for live vocals. A small dedicated PA system would be ideal. Not hard to learn. Figure maybe $500-1000 for a very basic to somewhat decent system.