Depends on how detailed you need the specs. That information would be on the Toyota main website.
Basically its a equipment and trim variance between the two models. This could also be influence by regional market - as not all equipment may be available in your area.
From the Toyota website:
Prius Model 1227 - JBL AM/FM/CD changer with integrated XM satellite radio, MP3/WMA playback capability, hands-free phone capability via Bluetooth wireless technology and eight speakers; three-door Smart Key system; leather-trimmed interior; heated front seats with driver lumbar support; step lamp; illuminated entry; driver and front passenger water repellant windows; upgraded front and center pillar trim; plasma cluster; auto dimming mirror and HomeLink
Prius Model 1229 - JBL AM/FM/CD changer with integrated XM satellite radio, MP3/WMA playback capability, hands-free phone capability via Bluetooth wireless technology and eight speakers; three-door Smart Key system; leather-trimmed interior; heated front seats with driver lumbar support; step lamp; illuminated entry; driver and front passenger water repellant window; upgraded front and center pillar trim; plasma cluster; auto dimming mirror; HomeLink; 17-inch alloy wheels; LED headlamps with auto leveling and washers and foglamps.
Might be able to find additional info on Priuschat - a forum for Toyota Prius.