I am a domicile for a loyal companion, often a secondary structure, seldom requiring a mortgage. What am I?

Buoyant beauty born from breath, drifting through the breeze, a gentle giant in enchanted air, floating freely like a fanciful feather.

Another you appears in me, yet cannot leave, nor truly be.

People often traveled the Silk Road in these, just like the Saharan salts, or a group of camels, Gypsies, or another traveling group. Nowadays, we think of semis, all paired up in groups on the road, especially when country is on the radio.

I'm worn in pairs but have no feet, I serve you well on court or street. Though I have a tongue, I cannot speak.