+1; cold side is relatively easy to fab up. Just be sure that any pipes under boost have a lip or "tits" or something to keep the hose on that end from coming off.
The best you can do is to get an idea of the angles and bends you'll need, and get a kit that has most or all of the parts. Sometimes you need a really short bend, and you'll just have to cut something anyway. A "U" or "J", for example, can be cut into two 90* bends, etc.
Ideally, you'd want to weld or have welded pieces where practical to minimize the use of couplers. However, you also need to keep in mind the ability to install and remove entire sections. Of course if you use a lot of couplers, this is not an issue.