I use a Yamaha EMX5000-12 powered mixer which has TWO effects processors, and use a small amount of plate reverb for general ambience, but if you need to get seriously big for a ballad or spacey tune, an echo (tap tempo-ed in time with the music) is, BY FAR, superior than drowning your voice in reverb. Just make sure you switch it off at the end of the song!

BTW....... the new mid-line Yammie powered mixer ( the EMX5014C) only has one FX processor (but six compressors).... you have to go up to the EMX5016CF (about $1k) to get the two processors, so a used EMX5000-12 makes a cheaper alternative. Massively powerful (2X500W), very flexible (on-board mono subwoofer line out, every insert point imaginable), I love it!