If you are for real, here are your major problems:
1) Your speakers don't match. That is a HUGE issue. Not only are they not tonally balanced, they don't play at the same levels (spl/dB). The sound is all over the place.
2) You've got inexpensive 3 way towers that give you a lot of punchy type of bass. Since you're used to this punch bass, you may never fully appreciate a good subwoofer. I'm not seeing funds in your future to really ever obtain a solid subwoofer - ie. $500 and up. You are correct in that getting rid of your $199 KLH towers that probably have 12" woofers will eliminate your bass. What you don't want is to go out and buy a cheapo $199 Onkyo entry level receiver, $300 in Klipsch bookshelves, and a $150 subwoofer. Although you'll have timber matching, you'll lose that punch bass you're used to.
3) Money. You simply don't have the budget right now to upgrade to a point where I think you'll be happy. No HTIB system is honestly going to put a smile on your face. You'd be much better off going with a setup like Jaxvon has - all Venturi type bookshelves with a HSU entry level sub and Pioneer 1015 receiver. The problem is, your center channel is decent quality. If you don't stick with Klipsch, you throw out the possibility of integrating the Klipsch with anything else. Klipsch speakers don't mesh with any other speaker. They're too efficient. Plus, they're horn loaded speakers.
4) Repetitiveness. It seems like you're getting a lot of feedback on your 15 threads, but keep asking the same questions over and over. I've got a great idea. List your entire system on ebay for $375 and chuck the entire thing. Then start from scratch and max out your Discover card. You can make payments and not have to listen to us preach what to do. You do have $1200 or so credit on your Discover, right?
5) You still haven't told me what year you graduated high school.
6) You must quit telling us you own Bose. Bose is not a word in the dictionary. It does not belong in your house. Chuck it.