Melting large amounts of chocolate. Tempering Machine options.

So, I am getting an order for 900 cake pops this week to be ready at the beginning of October.  For regular size orders, like a dozen or so, I would just buy the Wilton chocolate and use the microwave or double boiler to melt it.

But with such a big order I am thinking I need to be much more efficient.  Does anyone have any experience with a tempering machine?  They are very expensive.  Is that the best way to melt large amounts and keep the temp so I can dip?

I need something I can be sure will melt the chocolate properly for a long time so I can work quickly.

Also, can anyone recommend a good white melting chocolate.  I use Wilton.  But, if I buy in bulk, they are too expensive.  Thanks.