Spiritlite :) congrats (...again
LOL!!! )
When I was married, we also had a 2nd public ceremony and I had to figure out how to manage it. Simplicity was the key. If in doubt, I would choose the simpler or more classic...and usually vastly more affordable...option. LOL!
The potluck is a great idea! I love that...I would just add 'no seafood dishes please as the groom is allergic'. Afternoon is the easiest...just cake and coffee/tea...perhaps finger foods or side dishes if you want to keep things simple.
I think the simpler, the better for the ceremony. Let others pick some flowers or get silk ones @the thrift store...Pick a charming house of worship or outdoor setting as you prefer...and let the occasion speak for itself. Add some lovely background music (on CD is fine if live not an option)...
Pick the rings, pick the cake, pick something lovely to wear that is affordable, flatters and could be worn again...and you're done ;) except for showing up...
A nice suit the groom can re-use...much nicer than the tux unless you are going very formal...and if you are busty, a nice tailored suit or dress, or a slimming bias-cut dress will do wonders.
For favours...something simple, like sachets with a handful of white jordan almonds are classic and can be put together yourself with some netting and ribbon.
If you stick to something simple and classic...and then add your personal touches...it should take the pressure off...and keep the focus on you two
I'm sure it will be just lovely ;)
peace & blessings,
7L