Hi,
Yeah, I think svg backgrounds on a section are the way to go, you could even take the the negative space approach and use a .svg white vector for above and below to 'knock out' the shape you want, rather than have a colour svg, and fill the area with a bg gradient as above.
Alternatively you could use an inline svg and style that yourself, browser support wise could be limited here though.
Would look amazing with a subtle animation on the waves and/or gradient.