General question about selecting ICs

[negativefx]

I was looking at a few of the designs that have popped up using the LF442 so I went to place an order at  Mouser and ran into an issue I get all the time.

LF442CN or LF442ACN?

There's some sizable differences with them:  ACN has higher rejection ratio, lower offset voltage, lower bias current, and higher supply voltage.  It's also $5 vs $1.37 on the CN.

What can I do to ensure I order the right LF442s?  Not necessarily specific to this chip, more in general, what is the process to determine the appropriate IC or transistor when you get all these options?

[PStevenson]

the appropriate way to select the right IC is to get the cheapest version.
this may sound a little flippant but this is the way things in mass production (or even smaller production runs) typically get selected unless it's some extremely high end piece of gear.

within the narrow audio bandwidth guitar stuff typically has,  things like CMRR don't matter.
supply voltage is pretty self explanatory - if you're going over +/- 9v don't get a chip that only goes to +/-9v

the bits on the end (eg CN/ACN/AP/etc.) just refer to the class of IC and the temperature grade eg.
A - electrical grade A
C - commercial temp range
N - dual in-line package (DIP)

C - electrical grade C
N - DIP