Noob, need help please

You should post this question in Home Theater.  You should get many answers over there!

One person's opinion that a center channel doesn't add much is not a consensus. A center channel is not a must to get the system up and going, but if you want to maximize what you have, you should at some point get one that matches your mains. The Klipsch model you mention should work well with your mains. By all means, get as good of a receiver as you can at this point, even if it means delaying center channel purchase. Do not rule out a center channel speaker as a purchase because one person said it is not worthwhile. I have set up with and without (using phantom center), and it was definitely better WITH the center channel. Just MHO. I have been out of home theater for a while, so I am not up on the capabilities of the newer receivers and what is good for that price. 

For maximum enjoyment for HT, I think a center channel speaker is a must but not to get you up and running as mentioned.  Any of the midlevel AVRs from the major brands will be a good start and will the brains/engine in your system.

My suggestion would be to join  https://community.klipsch.com/ and ask this same question in the "Home Theater" section.

Bill

A receiver has a radio tuner, a preamplifier for input processing, and a amplifier to boost signal strength for the speakers. An integrated amplifier lacks the tuner. Then you have separate preamplifiers/processors and amplifiers. 

In some home settings a 2-channel system can prove to work very well for both audio and video. If audio was the priority I would look into a 2-channel integrated amplifier with sub output. The center channel is often not necessary when using a well setup high quality 2 channel system.

I am under the impression that video is a primary goal, maybe beyond audio. If that is the case I believe that if going beyond a 2 channel for home theater I agree that the center channel is important to bring out the dialog in movies. 

Therefore I would look into the purchase of a used late model  5-channel receiver. Start out with you L&R and sub speakers. See how that works for you. Then add the center if needed for video. Consider the rear speakers thereafter. The fewer speakers needed the higher quality of sound can be purchased at any budget. I believe that in most multi-use environments (living rooms) a 3-channel, one with L&R&center speakers do well. A sub is nice for video. If one has a dedicated room then that provides other opportunities. 

Hope this helps. 

Yes your question really is how do I set up a home theater.  Take the suggestions above, or when you buy your receiver get advice from the vendors.