You sure can!
If you'd like to purchase an existing design with a personalize touch just choose from the "board size" drop down menu on the product page and select the applicable size + (Custom). By doing so a text box below will be enabled so you can add your requirements.
Once your order has been submitted a proof will be designed and presented to you via email within 5-business days for your approval. The first 3 proofs are are included in the purchase price. If more than 3 proofs are required a $15 service fee will be applied to your purchase.
Once you've approved your order your sign will be produced and shipped within 3-5 weeks.