-The first set you linked to is a flatwound set for seven string guitar, normal (electric guitar) 25.5" scale: I've used it in my bass VI-type instrument (see below which string went where), and I can attest it to be long enough for a string-thru 30" instrument, but the distance between bridge and vibrato tailpiece of the Fender/Squier VI is longer than a string-thru canal and might be too long for this set - the good news is it's not terribly expensive;
-the second one is for baritone guitar, 26 ~ 28.5" scale, and probably up to 30", but again, may or may not reach the total length required by the Bass VI's tremolo - this one is even cheaper to experiment with;
-the third one is a set specifically meant for the VI, but it's actually an EADGBE set: the chart on the product page on juststrings is probably precompiled for standard sixer sets, but wrong for this particular set.
The "conversion chart" for using baritone or 7 string guitar strings in a post-Anthony Jackson "standard" 6 string bass tuning is the following
g: x x B E A D G B (E)
b: B E A D G C x x x
In other words:
-find a source for a short scale low B, or a way to get rid or tuck away the length of a long scale B that wouldn't be used on your VI - that means drilling a string-thru-body path just to place the anchoring point further away from the nut; or threading the string through a new ball-end and soldering it on the string at the appropriate length; or carefully unwinding the string at the other end to bring it down to size. As lz4005 wrote, you need a narrow end of the string to go into the tuning post;
-use a short scale E;
-if you want you may use the guitar B, E, A and D, tuned a step down;
-discard the highest two, F# and B (if the guitar set is for baritone guitar) or three, G, B and E (7 string). Or
, an easier way would be asking La Bella for a custom BEADGC bass VI set:
If you decide to try this, be prepared for the first frets being seriously crammed. If I wanted a standard sixer tuning in a short scale, narrow spacing instrument, I'd probably convert a 7 string baritone guitar because they have wider necks; still the problems outlined above would require an appropriate address...-al...-ment...-ion...-ing.