LCD Panel replacement because of intermittent backlight

Same story that's probably been told 500 times, my backlight intermittently works. The screen looks fine when using a flashlight, and plugging in an external monitor works perfectly fine. The backlight will come on if you repeatedly toggle the brightness buttons on the lowest setting and will stay on for 10-40 seconds unless you bring the brightness up real high, in which case it goes out immediately.

I've replaced the inverter, and I've replaced the inverter cable. Same results.

So it seems like I have three options, from cheapest to most expensive:

1. Replace CCFL

2. Replace backlight assy (I assume he means assembly? recommended here)

3. Replace the LCD Panel

Seems like replacing the CCFL is incredibly complex so I won't bark up that tree.

So I'm left with either buying a cracked panel on ebay to try and extract and replace the assy, or just purchasing an entire new LCD panel.

So my questions are:

#1 - Given my symptoms and what I've done so far, could I be confident an assy replacement or panel replacement would fix my issue (if it's not the inverter or inverter cable, it seems like the only other possible thing would be the logic board. But an external monitor working fine should negate that, right?)

#2 - If I go the route of buying a cracked screen and replacing the assy, how difficult/obvious is that?

#3 - If I go the route of replacing the LCD panel, does it matter which kind? My research shows there are four kinds of displays. I have a LTN133W1. iFixit doesn't mention which one they sell. Am I OK buying any of the four, or do I need to replace mine exactly?

Thanks for your help!