There is a local mega church being built and they have asked me to bid doing all the interior and parking lot signs.
parking lot signs are easy if they aren't wanting custom as you can purchase from Gimco standard parking signs for Handicap, Handicap Van and reserved. use metal only unless they have some weird custom idea going on for something high ended.
interior, what kind of interior? restroom/office signs? if so, ADA. you can have anything in ADA from stock off the rack to custom so it all depends on what they want