I agree that you definitely need to listen to the speakers before you buy. What area of the country do you live in BASO. Paradigm is a fairly well distributed brand and should have a dealer somewhere in your area, unless you live in a rural area or something. Even if you have to drive an hour or two I would recommend it. The Paradigm set you are interested in is going to retail around $15,000 or so. I may be slightly off on that figure as it has been a while since I priced Paradigm top line. KEF speakers are generally well regarded on this forum also, but harder to find a dealer in certain areas of the country. If you must buy sound unheard make sure you get something in writing that states you can return the speakers if you are not happy.
I have listened to the Sig 8, but this was a few years ago when they first came out. They are very rich and detailed and their highs are right up there with some of the best. Very good tight bass as well. You might also consider asking around the forum in the Meet Forum to see if anyone might have either one of these setups in your area. They may allow you to come by and have a listen.