Here is two sweet ETB cards

Gulf Squid

Whirlpool Rider

Sweet budget deck. Seems like a lot of fun!

About Pyromancer's Goggles: This card is really nice if you have many many red cards in deck, however, you only have 9 targets for the goggles of which only 4 to 5 are worth being copied and those cards won't make a huge game difference (except Ultimatum of course)

I'd rather suggest Dictate of Erebos for this deck since it's quite budgety and super effective! Phyrexian Delver or Body Snatcher are also great additions. Just cheat your creatures in instead of casting them. I would also play Outpost Siege or Impact Tremors (maybe also Blood Artist so every flickering is gonna have even more value. Some Sac Outlets like Goblin Bombardment or Ashnod's Altar can also help triggering your commanders ability and have nice synergies with the edict for example. Hope this helps!