Here's my approach to building a template:
1) What jewelry do I already have or are affordable on the merchants that boost 'exotic' bonuses (things like casting/melee speed, stat caps, power pool, heal bonus, style damage etc). Put these into Korts. Usually you can already get a feel for how things are going.
2) How many pieces of Dragonslayer do I want to use? The Dragonslayer chest is usually very nice. Other items may or may not suit your template. Two tends to be a good number and keeps farming down.
3) Do I need Dragonsworn crafted armour with the extra slots? Do the extra slots actually help my template? Usually yes.
4) Do I want to use the CL5 weapon? Usually yes.
5) Can I now make a balanced template by SC'ing the crafted parts? Usually no, unless you're lucky. So then it's time to juggle the jewerly and make some choices about what 'exotic' bonuses you'll have to sacrifice to make way for more mundane stuff.