Need help with block design.

Hi,
I'm going to mill two blocks soon, one for Cpu and one for Gpu.
Which dimensions should i go for? I'm thinking about 5x5cm for the Cpu block and 3,5x3,5cm for the Gpu block. Do you guys think its good enough?(Dumb question maybe :D)

These images is from Askers evaporator design:

Bottom: http://upload.stormaz.servebeer.com/Pandrone/botten.jpg

Middle:http://upload.stormaz.servebeer.com/Pandrone/mitten.jpg

Top:http://upload.stormaz.servebeer.com/...ne/ovandel.jpg

That is the design im going to use for the evaporatorblock.

Its going to be used o´for an AMD system and a R9800pro.[IMG]

well it is a nice design and should work well..i personally dont like twin flow paths,because i find the refrigerant will have a likely chance of going though one more than the other.path of lease resistance.thats why i always try and use a single channel path.this forces it though the way i want to to go.
still you never know unless you build it.and i sometimes build things that shouldnt work,but they do.so go ahead and build it the way you have it,and test it and see how well it works.
but it should do a good job:D

Now it struck my mind, that i have to run the capillarytube inside the lowside(suctiontube or what you call it). Any ideas how to make that nicely?