I also like a cup that fits on the bottom of my water container; there are several variations available. A Snow Peak 700 (titanium) is the lightest, toughest, and most expensive, but it cuddles nicely around a 1 L Nalgene or a lighter variation, a 32 oz recycled Gatorade bottle. Somewhat heavier, but considerably cheaper is a stainless steel cup (Olicamp is one maker). A very good water container is a collapsible water jug of which the most common brand is Platypus. Their one L version will fit in the cups mentioned above.

I have assembled a complete kit for coffee, tea, or boil in the bag meals by adding a Trangia alcohol stove, fuel, and the ingredients for that nice cup of tea (or Starbucks Via) to the above.

I do pay attention to container weight, because I am usually backpacking or hinking, and water is almost always the heaviest thing I am packing. Container weights of items like Nalgene containers can add up pretty significantly - I really like Gatorade or Powerade, etc. bottles for that reason - ust wish I could get something that has a full liter capacity.

I you are transporting by vehicle, you have much more latitude, but I don't bother with containers of more than about two gallons capacity. They are jsut too heavy and awkward - usually.

Hydration bladders or hydration "systems" are just too darn fiddly for me. KISS applies here.