Those speakers aren't powered are they? That Fiio isn't going to get anywhere near the amount of power that you're going to need to get much out of those speakers.

A basic amplifier like the Lepy LP-2020A would get you a lot closer to the power demands that you need.

For a bit more I like the SMSL SA50. It's nicer to use and has a bit more power than the Lepy unit.

For a basic explanation of why that FiiO isn't going to get there... it pushes a maximum of 78mW (.078 watts), your speakers will need more power than that...to get to 87dB at 1 meter you'll need 1 watt.

You could grab cheap speakers from Bic America for most of your gigs. Their RTR line has pretty high output for the price. Something like the RTR 1530 (292$ for the pair). They output low enough (33Hz at -3dB) you shouldn't need a sub.

For an amp I might suggest an Audiosource for about 126$.

Or the SMSL SA-50 50Wx2 (66$), its a digital amp so it's super efficient. Any criticism people have about distortion in the highs is irrelevant because most dj equipment (like the 1530's) don't actually have especially accurate treble.

Best advice I've got.