No. The converter box program involving the $40 coupons is only for converter boxes that provide an SDTV signal. Boxes that output an HDTV signal are not eligible for the $40 coupon. The outputs on most of the coupon eligible converter boxes are RF, Composite, and in a few cases, S-video. To get HDTV, you would need a box with Component or HDMI outputs. But if you don't want to spend spend the money for true HDTV, you can still get a very good picture using an SDTV box. Most of the boxes will allow you to format the picture so that widescreen broadcasts fill the screen on your widescreen TV. It won't be HD, but it will probably look better than the picture you're currently getting from your 522 and 322.
You do not need a special HDTV antenna - but you will need a good antenna. How good depends on how far away the stations you are trying to recieve are located. Check AntennaWeb.org for info on digital stations in your area and antenna suggestions. I live within 20 miles of the stations I receive, and I've had good luck with the Radio Shack double bow-tie UHF indoor antenna (I'm not sure if it's still available) and the Philips compact amplified HDTV indoor/outdoor antenna sold at Walmart. All of the digital station in my area are UHF, if there are any VHF in your area, you might need a different antenna.