Welcome to the forum, Johnathan!
Yes, I'd say that's quite a jump. Sibelius 7.1 does indeed see Kontakt 5 correctly, so you won't need to hunt down KP4. VDL Template 6.0b will work within Sib 7, though I'm getting close to having the 7.0 version done.
S7S Template 7.1 supports the Sibelius 7 Sounds sample library that's included with Sibelius 7.
Yes, I'd say that's quite a jump. Sibelius 7.1 does indeed see Kontakt 5 correctly, so you won't need to hunt down KP4. VDL Template 6.0b will work within Sib 7, though I'm getting close to having the 7.0 version done.
S7S Template 7.1 supports the Sibelius 7 Sounds sample library that's included with Sibelius 7.