I believe the TV Wonder add on board now supports mpeg-2 capture in MMC, I don't believe it supports all the timeshift features of the AIW, but definately one of the most cost effective mpeg-2 capture solutions. Of the two boards you mention, the AIW Radeon is far and away a better board than the AIW pro, especially at that price, it worth the extra $85 IMHO. Keep in mind that the Rage Theatre Chip captures YUV in hardware and uses Ligos GoMotion to compress to mpeg1&2 in software in real time, so you'll need a somewhat stout CPU for highest quality mpeg-2 captures.
Hauppage WinTV PVR is another capable board, but I'm not real familiar with their products.