You really need to decide upfront if you are going shifter or not. Each of the forms overrides certain abilities and then it comes down to just setting the starting abilities so that you can take feats which which augment the shapes. Many feats (like Weapon Focus, Improved Critical, etc.) will have no benefit in shifted form. Shifter takes some experience to determine which form works best in each situation, but can be a dominant and fun build once you get handy.
Dragon Shape is best in lower magic (<+6) environments since only armor merges into that shape. Other shapes worth considering are Kobold Commando (finessing HiPS-er), Risen Lord (crit immune, high damage) & Rakshasa (unlimited ice storms, uber spell immunities) which each merge all equipment except gloves.
Your main goal is to settle on the area where you would like to dominate (i.e. morphed attacks, casting, unshifted attack) before setting the starting abilities.
ZelleQyllvan's guide will help you decide if wildshape/shifter is what you really want to strive for. It contains no builds, but all the details of the forms are recorded on one place and how feats and skills are managed.
IMO adding an arcane tertiary class wiill simply dilute your druid casting power. You will also be limited to robes or constant switching. UMD would be a better way to gain access to non-druid spells if you just want a few buffs from scrolls/wands as support... that means rogue (or assassin) for UD and perhaps some sneaks. Monk is possibly the best cheese dump class. CoT will allow you to get Dragon Shape faster.
For elven shifter, you will get an XP penalty with any non-prestige tertiary class except wiz. As halfling shifter any but rogue will be a penalty. For just one dump at level 40, it really doesn't matter what class you select.
I am betting even vested with Zen Archery you will either be casting or attacking in morphed form and will rarely ever use the bow.
