The Wet Sounds XST-650's are on closeout for $399.99 a pair. bridge these on a 4 chnl amp delivering 100-150 watts rms x 2 and you are well within your budget.

The Kicker KMTE-S pods and a pair of KM6200 speakers can be had for about the same price and also bridged on a 4 chnl amp.

For a budget setup, I would pass on a $700 Class-A/B 2 chnl amp. Thats more then the OP wants to spend in all. For less money, there are more efficient Class-H amps that are marine built that will deliver similar power at the same load.