fairly good but aren't going to equal the instore rig you heard. Check the c/net reviews (& whatever you can find elsewhere) for HTIBs. I believe the best comments seen here have been for a couple of the most expensive. I believe conventional consensus amongst regular posters will urge you to find a decent receiver & selecting speakers from specialized speaker makers at or slightly less than those couple top priced HTIBs for results & satisfaction better than the prepackaged ones.
OK, here's the general pitch. Quality speakers (best that you can afford) are the key element. A $550 Denon is more than sufficient. You'll be better off cutting cost for the receiver. Please check c/net's receiver reviews. Many favorable ratings among the $200-300 price bracket. Time, technology & lots of competition have made receivers a greater value than ever before. Just don't try to get too chintzy.
The speaker dilemma could be addressed by starting with, for instance, even just two fronts from JLB. As budget permits you could upgrade piece by piece by adding like brand from the same series. Fronts 1st, then matching center, then either surrounds or subwoofer.
It is key to choose wisely from among stable, well established speaker companies. You definitely will want fronts, center & surrounds to be from the company's same series to be matched as to sound characteristics. The matching thing doesn't apply to the sub. There are quite a few speaker brands that get recommended here. Hope someone chimes in to remind us of the general list of common brand names.
C/NET highly recommends the Axiom brand, which is sold direct to customer with 30 day in home listening period. To go with my Denon, I have been so pleased with Paradigm speakers. They are widely distributed these days. No online sellers authorized for them.
So, without all the bucks up front to jump into the kind of fine sound you heard, you can achieve very satisfying stuff if you're willin to get into it spread over a time period. I feel we generally think that way will exceed the prepacked HTIB. Don't even begin to get misled into speakers branded by the component makers. They are just after thoughts.