It seems to me like you are taking a huge step sideways and wasting a lot of cash instead of just making a slow upgrade process with quality speakers.
A good subwoofer is a must. You don't have it now and you need it now. So, perhaps that's a good way to go if you have $1,000 to spend. For that money you can get a sub which can really fill in the lows with control and power which you are currently missing.
Also, at $1,000, you will get a subwoofer which will last you for years and years without you really wanting to, or needing to, replace it.
If that's not at all your interest, then a good set of replacement towers may make sense, but I certainly wouldn't recommend replacing several hundred dollar speakers with several hundred dollar speakers. You just aren't going to get an improvement with that type of cross platform jump.
I would suggest, that since you have a surround setup that is decent, that your goal for quality audio isn't going to be served with replacing everything at once, but by now focussing on high quality upgrades as your budget allows for it.
I think the number one spot people cheap out on is the subwoofer quite often, and systems easily reflect it with boomy bass or with a lack of the low end which is necessary to add a presence to the room.
Hold onto your money and get some more input, but that's my $.02.