I dont have high hopes for Territorial Gorger
Now, if you want to do something incredibly innovative with your custom card, like introducing a custom frame or weaving together text and image like some Secret Lairs do, Photoshop/Gimp is likely the way to go
Magic has more than enough self-mill to facilitate a swift flip, and I highly doubt you need much more than that to win with the proper setup
Serpent of Yawning Depths is a must-include in giant sea creature tribal decks
Abyss Proxy Shop offers premium Winota, Joiner of Forces MTG proxies printed on German black core paper, the same weight, size, and thickness as authentic Magic: The Gathering cards
Maybe now, I would wait for lower conditioned raw cards or just keep the graded card for future trades to lower condition (if I am desperate to buy the graded card)