First port of call for you, the Wc sticky at the top of this section, http://www.tomshardware.co.uk/forum/277130-11-read-firs...
Second place on your visit list, the W/c gallery, http://www.tomshardware.co.uk/forum/266324-11-water-coo...
Theres a few here have used Phantoms with varying degrees of success/coolness
$300 is the better end of your budget, kits start at around $140 but you'll need some extra radspace and a block for your Gpu as well so a fatter budget is a good thing in your case,
I also found http://www.evga.com/forums/tm.aspx?m=1663457&high=confi...
this tells you you can use fullcover blocks on those cards, but F/c's are expensive and can't be transferred to a new card so if you change card, you'll likely need a new Gpu block for that,
but the sticky covers most things you'll need to know right now and then we can answer any other questions you come up with
**Edit, green tubing is not a problem btw, lots of manufacturers make it
The sticky tells you how to calculate TDP of your components so you know how much radiator youi need, if you start with a 360 rad you should be ok but I always advise having more rad than you 'need' as it gives you more headroom, and also allows you to run your fans slower and therefore quieter,
If the barbs in the kit are standard the any 1/2 Id green tubing will fit, but remember to clamp to the fittings if you don't get compression fittings,
And you must decide if you want a fullcover block, or a universal one with heatsinks for the VRam chips