Are other forms of the imperfect subjunctive for querer (quisieran, quisieras, quisiéramos) also used in this context?

Hola Mikaela

Not in all subjects - it's more widely used for the first person singular (yo), although you may also hear it in the nosotros form: "Quisiéramos una habitación con vistas al mar." for example, or with usted: "¿Quisiera usted tomar asiento? - although with usted, the "querría..." form would be a bit more commun.

Saludos

Inma