In Biarritz there are plenty of surf shops hiring boards. While some will try and give you foam boards, a few will have better quality ones.
On Rue du Port Vieux there are three or four shops that all rent surfboards. The boards vary in quality and shape.
Shops that I know hire better boards are:www.surfin-biarritz.com
(on Rue du Port Vieux)www.oceangypsysurf.com
I have heard great things about them but they are in Labenne so quite far away from Biarritz. Labenne is on the train line from Biarritz though so if you were desperate you could stop off there on your way.
If you want to couch surf then have a look at this: www.couchsurfing.org
There are two campsites in Biarritz, one near the sea called Biarritz Camping (28 rue Harcet) and the other is out by the airport, Camping de Parme.
I'm currently doing a daily eye ball surf report for MSW at Cote des Basques. You can see it on the Cote des Basques surf report page or go to my website to see the last 10 reports too: http://biarritzairporttransfers.com/bia ... eport.html