Bob! For 8x10's at 300ppi you need about 7.2 MP, so the FZ7 falls a bit short.
But, it's so close at 6MP that the small amount of upsampling from 2816x2112 to
2400x3000 for the 8x10 might not cause a noticable loss of quality.
Something else to consider: Does the FZ30 have features that the FZ7 lacks that you might find useful enough to make the FZ30 worth the price increase?