Don't get too hung up on one particular area of comparison between brands, noise is not the be all and end all of a good photo, think beyond that to the way one brand appears to have more appealing colours or how many of which brand that you hear about being repaired regularly. Start a database and spend time and then more time researching camera models / brands and then start checking the boxes in that database that are important to you.
head down to your local camera store and look at and hold every camera you can, get on the net and read every review that you can. Spend plenty of time on AP and ask questions (as you are doing) because sooner or later someone will have the correct answer to your questions.

Research research research.