Ciao Stefano,
The Jag 94 is a 1cm narrower than the Blast (61 vs 62cm), you´ll have more top speed, slightly worse manoeuvres, a bit less planing power due to the more traditional outline. I also do not think that 8.2 is the ideal size for that board, it´s a push already for the Blast...hmm, I would say stick to the Blast and maybe upgrade the fin to a faster model if that is the only thing you miss?
The Freewave is a good choice for jumping, but so is the Grip or the Stubby and maybe you will want to ride some waves too? for your weight, 100% for sure the 75L size in all three - except you mention a 5.7 sail, which is definitely too big for 75L and will just fit ok on a 85L size? if it´s really stronger winds like 15knots upwards, I think with a 5.3 or 5.0 downwards, you should be fine on a 75L board.