help me build my system, i have some technical questions

first off, i'll be water cooling the parts in my sig. why, b/c i want to. low prices would be nice, but i am expecting to spend about $300 total once i have everything. i've done lots of research and so on to the questions:

1) how much water should i expect to have in a typical WC system? i will be getting Swiftech HydrX Coolant and it's says it's effective for 33oz of water. so do i need 1, 2, or 3 bottles or what? would 1/2 gal of water be a safe guess for the water volume in the system?

2)so far everyone seems to like the 7/16'' ID 1/8'' OD tubbing better. it's a happy medium b/c of it's soft, flexibility, has a low pressure drop, and it maintains good flow. the prob is, most cpu and gpu blocks come with 1/2'' or 3/8'' barbs. do i just slap on some kind of adapter? in theory if i attach a smaller adapter the water flow will speed up, in turn creating more pressure. i think this could pose a problem, potential leak problems, unless i can get the block i am looking at with 7/16 fittings?? http://www.dangerdenstore.com/product.php?productid=28&cat=58&page=1

...umm, i think that's it for now. i will add more questions as i think of them, i will definately have more.

1) I had a small res in my last setup, I think I used ~0.5 Liters of water. 1 bottle of Hydrx will be enough for at least 2 fills, maybe 3.

2) 7/16 tubing will stretch over 1/2" barbs fairly easily.

well that was quick and easy. thanks! i'll have more questions soon, i'm sure.