Does anybody have contacts with these as a friend of mine would like to rent a beautiful house in Thawil for rent for 1 year to expats and would like to go through relocation agents.

My company used Touchdown Relocation Services here in Zurich. Could also post on Homegate.ch

good luck

Look at similar properties on homegate.ch - you'll find indicative prices and you will find agencies through whom you can rent the place.