Hi what the pluck,
I'm not sure what arco is. Would you please explain?
And are you looking to rent in a specific part of Greece (city)?
I have dealt with a place called "Manos Backline Services". They also offer instrument rental (as well as lighting, sound, etc), but I'm not sure about your specific instrument.
If they don't have it, they may likely be able to tell you who does.
Their web address is www.manosbackline.com
Tel: +30 210 822 6333
Fax: +30 210 881 5769
Cell: +30 693 290 9717
They are located in Athens.
I hope this helps.