Assuming a standard 16 ish lands that gives a whopping 16 spaces left for support cards, disruption and filler
All four starter decks have active communities
This means these legendary creatures cant be your commander : Emrakul, The Aeons Torn Erayo, Soratami Ascendant Golos, Tireless Pilgrim Griselbrand Iona, Shield Of Emeria Leovold, Emissary Of Trest Lutri, The Spellchaster Nadu, Winged Wisdom Rofellos, Llanowar Emissary You also cant play any card with a silver border or acorn stamp as your commander
Orvar, the All-Form At first glance, Orvar is just a better Mistform Ultimus
Some other sites that sell cards that can also be used as a reference are ChannelFireball, Star City Games, and Card Kingdom
We're well and truly in "great out of the box" territory now, and Silverquill Influence requires no upgrades to be a fun, competitive deck at your local game night