I prefer a cohesive look as well. But that doesn’t mean they all have to be exactly the same, just coordinate with one another. You just want to make sure all the signs look like they are meant for the same wedding. But, this is your day, and really you can do anything stylistically that you want! If you like the look of completely different signage, definitely go for it!
They don't have to match, just look cohesive. My welcome sign and seating chart matched my invitations and were done on poster paper placed in frames..my cards & gifts sign along with tables names are done on acrylic or glass with vinyl in the same color scheme as other signage...it works for me, so do what works for you.
Hey there! I think it looks really polished to have a similar look and theme for all of your signage which includes the materials. For DIY, I recommend either paper or acrylic for the best professional looking results.