If you're going to use the TV's own speakers for now (I remain hopeful you'll eventually see the light re decent cinema sound!), the Toshiba would be the best of those two options - despite its diminuitive dimensions, it's got some of the best flatscreen speakers around. Don't be disappointed if they don't offer the heft of your subwoofer-packing Sony CRT, though - there was a lot more space for speakers in those big-'ole sets...
The Panasonic would have the edge over the Toshiba for black depth and possibly a slight advantage on motion-handling, but otherwise the Tosh is visually an excellent, Full HD set - it'll thrive when you upgrade to Sky HD.
Just make sure you shop around - we knocked a star off the Toshiba's rating for being overpriced: make sure you pay far less than the original £1700 list price.
EDIT - Sorry, just saw your second post above. Go for the Tosh!