We’ve got quite a handful guilds getting active as of late, especially in preparation for 8.3 and eventually Shadowlands. Here’s a sampling of the Horde guilds. You did mentioned you were rolling Horde at the moment, despite the Dwarf avatar.
I know < hug > is looking to focus on raid and mythic dungeon content. So is < Life>. And < Daydreamers >. Just peruse the forum posts and you’ll find lots of Horde guilds that also at least dabble in progression content.
And if you decide that the Horde isn’t for you, there’s also Alliance guilds like < The Fortyseventh >