Buying through a local A/V specialty store will always be more expensive than online, but they'll usually provide services which you can't get from an internet reseller. Like free loaners if you have to send something back for repair. Depending on what they have in stock, free loaners for auditioning in your home might be available.
Personally, I have no experience with wireless speakers, but Paradigm is a well regarded brand. How good they sound is what matters. Don't forget that they'll sound somewhat different in your room from how they sounded at the dealer, so you might ask to have an in-home audition before you commit to purchasing those particular speakers. Minor sonic problems are likely to be taken care of by the Audyssey room equalization software in the Integra AVR, of course.
In larger rooms, two subwoofers can help to balance the sound, but you shouldn't assume one will be in the front and one in the back. Their best positions will be determined by the room's acoustics.
Marantz SR7009/7.1.4/FH+TM/DefTech PM1000/LCR+TM amped