The MAX6675 doesn't need a ADC to interface with a PIC.
You just shiftin the serial data and it reads pretty much directly in degrees C on an LCD without too much else.

This is pretty much all the code involved...

Code:
'Alias pins - MAX6675 temp sensor
MXSCLK  var     PORTB.5   'Clock
MXCS     var     PORTB.4    'Chip Select
MXSO     Var     PORTB.3   'Serial out


 'Allocate MAX6875 Variables
MXTemp   var     word    'raw data from 6675/type K sensor
TempC   var     word    'converted to degrees C


'-----------Read and display temperature from MAX6675-----------
MXCS = 0  'Chip select low
shiftin MXSO, MXSCLK, 0, [MXTemp\16]   'read the data to MXTemp
MXCS = 1    'Chip select high
TempC = MXtemp >> 5   'right shift the data 5 places to get degrees C (Read the Data sheet)
LCDOUT $fe,2,"Temp = ", DEC TempC, "degrees C "  ' Spit it out on an LCD
Works for me...

Steve