i used the focal solos for about 8 - 9 months of almost exclusively piano and strings. imho they did not have the detail in the mids i was looking for and traded up to the PMC TB2A new they are about $500 above your current budget (new) i went with the active version as the d-class amps that come loaded with the TB2A that to my ears give lots of detail.
the below link is to the newer version TB2A which i suspect are more expensive than the version i and most others are using and still stock in most places with pmc gear.
PMC Ltd
The TB2A well worth looking at in terms of piano and strings and also superior low end compared to the solos imho. the pmc transmission line really does delivery a surprising amount of genuinely extended low distortion bass.
spek
but don't get me wrong the solos are o.k value and one could go a long way with them i just found for a little extra $$$ i got a lot more detail from the TB2A and would have saved myself $500 if i had gone with them in the beginning. v."natural " sounding to my ears and great with acoustic instruments.
ps the other monitor i have heard good things about for this type of production (which i have not hear myself )is the klein and hummel 0100 that i think would also fit your budget.
KLEIN + HUMMEL, O 110 - Active Studio Monitor
ps re: budget spend more now if you hear a sound you feel is right and in the long term save $$$