Do I need another wheel for my disc brake?

I am a little confused about what I just got myself into...

I am building a Felt Twin with Monarch forks and the disc brake kit from Venice. Norm said I should be good to go with the hub he sent me for my 12 gauge spokes, all I need to do is have a bike shop switch out my hubs for around $40-60 bucks. So I called a local shop today, and I got a different story. They said it's going to be very expensive and probably would be better off just buying a whole new wheel with a disc mount hub for $150+. Another concern I have is why is axle in the hub I received like half the size of my Twin's front axle? It seems like it wouldn't be able to take much weight at all.

Comparing the two hubs, the one that I got for my disc brake is much smaller, so I think I will need new spokes wouldn't I, otherwise they wouldn't be long enough.


Can someone please inform me of my options? I really don't want to buy a whole new wheel just for the damn hub, but I already put in a $100 for the brake kit. I probably would have just gone with a drum/wheel combo from pirate if I knew I would need a new wheel.

Thanks for the input. I tried calling yesterday but no answer, so I posted this to see if I could get a faster response. I'll look into lacing it myself on you tube, that would be nice to save a little on labor.