Loop order doesn't really matter all that much as long as the res/T-line comes before the pump. The most your temperature will differentiate from any two points within the same loop is like 1-1.5C. This was proven by one of the math/physics wizards over on the XS forums and can be looked up on Wikipedia.
The best way to route your tubing is to just use the least amount of tubing possible.
The best way to route your tubing is to just use the least amount of tubing possible.