Hi there,
Your project sounds like great fun!
Id be happy to take on your project and have done lots of Invitations before.I would use Adobe Photoshop to do yours, it will allow for all the nice details to be added to the background like burn marks etc.
I am a Graphic Designer of 20 years and am just moving into freelance design Full Time so i have lots of time on my hands and give 110% to your project!
I also guarantee my work so if your not happy, you don't pay.
Please feel free to contact me anytime, I am on Freelancer mobile and will make every effort to get back to you immediately.
Regards,
Garth