go to various places that sell these and have them for demo , also maybe take a closer look at the systems your friends might have . alot of these box systems aren't awful , but i do think that the majority of them don't get loud enough and loose detail and nuance (for music). keep in mind these box systems are built for movies and seldom does any system do all things well .
personally i'd avoid all home theatre in a box solutions like the plague. i'll admit some do not sound half bad but the build quality is crud compared to what you could be spening money on.
picking out an a/v receiver, speakers, and a sub can get you a system that sounds at least equal (but normally better) to htib solutions while giving you a system that isn't all plastic.
as suggested you should go to a place that displays these products and listen to them yourself as your ears are the only judge. what i like may not be what you like.
in general for your budget you might want to avoid sony receivers. i've heard bad things about their receivers under $400.
however on the plus side for sony they do make a decent set of tower speakers for the budget concious. i believe sears.com still sells them. we got two 3.5 ft tall speakers in a box for $100 and they are boomy enough to not require a sub (not even amped!). definitely worth a look into.
personally i'm using a pioneer vsx-30, klipsh quintet IV 5.0 set, 450w klipsh subwoofer....but when i bought the speakers alone they were about your budget. were definitely worth the money though in my opinion but there are other choices out there for lower budgets.
if the speakers you're looking at seem to blow your budget then heres another thought: get a receiver, sub, center, left and right setup (3.1) now and then if you feel the need, upgrade in the future. keep in mind that most pc sounds (exept movies and games) arent surround sound anyways.
i think maybe your dollar would be best spent on putting together a 2.1 with the possibility of adding pieces to get a 5.1 ,6.1, or a 7.1 if that is what you want . start with buying a receiver that has the future capabilities you want. i agree that cheap sony's are probably best to avoid , onkyo isn't so hot lately either . amazon.com is a good place to look at some things , the reviews people write are relevant regardless of where you buy it .
i had for many years just a 2 speaker stereo setup and a good Forrester for movies and games proved to be an improvement over tv speakers . i also might add that a stereo does give the perception of direction and such to do with sounds , but Dolby pro-logic has a couple more dimensions naturally in sounds being directional.
if you would like to go for the box system , maybe yamaha is worth a look , their receivers are descent and you could upgrade to better speakers later and the speakers that yamaha would supply would be ok in the mean time .
i haven't heard any klipsch speakers yet , but it on my to-do list , i have heard lot of good about klipsch . if you don't care for klipsch i might recommend a look at jbl or infinity i think is now owned by harman , the parent company. polk might be a good one to check out as well .
i think the money is best spent on a system that doesnt require a subwoofer.
most people cant get their front left and right speaker down below 30hz
get yourself four speakers that can get down to 20hz
two for the front left/right
two for the rear left/right
then find yourself a receiver that allows you to mix the LFE channel with all of the speakers set to 'large'
the only way this wont work is if your receiver does something really stupid when you turn on the LFE mix option.
all speakers should still be able to drop down to 20hz at an individual rate, as well as a group effort.
the LFE channel simply gets mapped to each speaker with zero change to the crossover of each speaker.
that way.. you could set a subsonic filter for the LFE channel (but i dont think any of the receivers have that)
LFE crossovers give you the choice to use the subwoofer for bass because your speakers are not going to produce the bass.
and most of these crossovers go down to 40hz and stop.
real LFE effects are in the range of 1hz - 20hz
and some might argue that real LFE effects are actually 1hz - 10hz (or 1hz - 15hz)
the mistake is terrible.
and anybody willing to follow the correct advice..
you will probably do the same thing i have had to do most of my life.
when you go to somebody elses house and play a movie that you have already watched at your house.
you sit and wait for all of the very good audio moments.. and you witness the audio system completely fail on the 3d portion.
sure.. your friends $800 subwoofer can play the 20hz note.
but it didnt have ANY of the stereo or 3d effects that your audio system has.
so you might sit there and lower your head into the collar of your shirt.
you drag your friend to your house and make him/her listen to your system, using the same exact movie, and specifically point out the differences that their audio system simply could not do.
your friend's brain might be completely and utterly hyperactive that they dont even hear the 3d surround effects.