Inquiry about Custom Printed Coin Envelope

I need custom printed coin envelopes in two specific sizes: 3" x 4.5" and 3 3/8" x 6". The design should include our company logo, website URL, and some fun graphic elements. Prefer single-sided printing with a simple thank-you note on the flap area.  
 
Require quotes for both black & white and color printing options. Initial order quantity is 500 pieces for each size. Material quality should balance durability and cost-effectiveness.  
 
No urgent delivery timeline, but samples approval is necessary before mass production. Please confirm your capability to handle custom envelope sizes with precise printing alignment.