Dado Blades...

What are you planning to use it for? I have both styles, and use each for different tasks. The wobble is great for ROUGH work, like making half lap joints in framing type materials. But they do not produce anything close to a smooth cut. For furniture quality work, the stack head is far superior. Decent stack sets start around $100 and go up from there depending on the number of teeth/chippers. Buy carbide.

If you'll be making a lot of cuts into sheet stock, like bookshelf or cabinet side panels, it's easier to take the tool to the work. For this a router and one of the the slick "clamping tool guides" is the way to go.