You might want to make a series of purchases, instead of all at once.
Spring for the LG 55" 7600 first (or it's cheaper brother 6700). This has all the streaming you will need...so you dont need a box.
And get yourself a Wireless N Router. This should be rather easy....just follow the crowd and focus on ease of use and reliability.
Then a cheap Blu Ray Player, like the Sony BP-185.
Then start auditioning speakers. I agree with Otto, speakers are important to the sound, moreso than just about anything else. If you dont know where to start, you are going to have to take someones advice. The inexpensive Energy Take 5 system is very popular and for good reason. I like the Realistic Minimus 7 and Minimus 77, too. There is also the Boston Acoustics HD-7....another one I like. Generally what you are looking for is a 2 way speaker with a 5" to 8" woofer and a tweeter. I personally like soft textile dome tweeters, especially silk. Very smooth. But then again, Film soundtracks have somewhat different requirements than music listening. Often metal domes are favored for Home Theater duty. All that being said, anything will work, really. And personal taste comes into it. But just know that you dont have to spend a fortune to get good sound, and sound that you personally like. And that is what matters most, that YOU like it.
A good plan is to get a less expensive used HTIB, to get you started and then shop for speakers at your leisure. Then shop for the perfect A/V receiver to power them later, after youve picked out some agreeable speakers and replaced the HTIB's included set.
I wouldnt spend money on calibration. Instead you can burn a freebie disc like the AVS 709 or Getgray. Or the Avia disc is pretty inexpensive. Or Disney Wow! for BluRay (though you really dont need a BluRay disc to calibrate the settings). Follow advice from people in the LG 7600 thread with regards to advanced settings, and change those before going through the disc.
The Display & Router should come first. Get a BluRay for it's quality source ability. Then work on the sound.
Panasonic AX-200u / Optoma Graywolf 92" / Draper Luma 92"
Samsung 51F8500 Plasma / Vizio M422i LCD / Vizio GV42LF LCD / Vizio VP322 Plasma
Sony S790 BD / Panasonic BDT220 BD / Roku 2 XS & HD-XR / PlayStation 3
Oppo 983H Anchor Bay VRS / Denon 2930CI Silicon Optix Reon / Panasonic S97 Faroudja Genesis / Oppo 970HD Mediatek
Panasonic LX-900 Laserdisc / Aiwa MX100 Multi-region VCR / JVC S7600 S-VHS