I have to say, Studio X at Wizards of the Coast (WotC) has been hitting some serious home runs when it comes to Gruul commanders, to the point that I now have slightly more Gruul than Golgari Commander decks in my collection, despite being a huge Golgari fan for decades
Here are the general rules of thumb I follow when addressing this question myself: If my deck has green, the best mono green mana ramp spells are usually better than my multicolor options
$18.24 $15.00 $4321.00 Ionos Bellibolt ex (#188/159) from the Journey Together set stands out as a highly valuable card thanks to the combination of a fan-favorite Trainer and the charming, rotund Bellibolt Pokmon
The Ward ability keeps him well-protected from cards that hurt or eliminate chosen characters, forcing opponents to fight him head-on
You could certainly place a rounded rectangle filled white and stroked in black onto a scan of the image file, drop text on top of that, save a copy as a bitmap, and use that in the GFUI for an engrave