You are not printing alot right? Think going to a printer will be expensive.
DIY... There are many ideas fr the internet. Decide on the theme you want, google for pics of the theme. Then you can google for layouts and wordings. Piece it all together using a computer programme (I used powerpoint). I used downloads fr scrapbooking sites for my background.
If you want, I can show you pics of the invites I've done for my kids so far. Give me your email if interested.
Hope that helps!