Do you know where can I buy knobs like these?
(on the web)

some dude on this forum was asking about wooden knobs not too long ago, someone gave him this link. http://www.guitarpartsresource.com/middle_bass.htm Good Luck.

Those look like metal knobs (Fodera uses metal knobs). For plain wooden knobs or wooden knobs with whatever shape you desire, made with whatever wood you'd like and with lams/inlays and/or all sorts of bells and whistles, I'd suggest you contact Roger at THG knobs at http://www.thgknobs.com/

Diego