I haven't seen the Elvira board but I did see the Shatner and it looks pretty good, if I do say so myself. We ended up going with only two board this year, the Tia Carrere image that worked best was too low a resolution for a billboard and Katee Sackhoff had to postpone her visit (she will be here next year). so we opted for just the two boards.
Shatner's board is the one that changed. The headline used is one that was brought to the table by the event organizer early on. It's pretty funny.
Now I have to drive around and check them out - ROADTRIP!