If you want a pendant that is definitiively strong enough to secure your boat in storms, then you'll need something more than 1". The math behind this was posted here on the forums
about 2 months back, & it confirms what some of the operators of mooring fields in the NE have stated about pendant sizes. Who commented in Professional Boatbuilder
magazine that dual 1" pendants were about the minimum required for serious storm usage. Check back issues from the early 2000's for this.
It has to do with the amount of energy you're asking a line to absorb within length X, given diameter Y, & based on the line's stretch characteristics. All of which can be caluclated, exactly as is done for snubbers. At least when people know how to do this math, & take the time to run the calc's.
And in this circumstance you're asking the line to do a job akin to that of a snubber, but in a much shorter length of line. So that in order for the line to be able to absorb that much energy, it'll have to be significantly thicker. As a snubber for the same boat would be significantly longer, though a bit thinner.
isn't tough to source. For if naught else you can contact the manufacturer. Who no doubt also would be happy to splice you whatever diameter line, into whatever configuration you'd like. In addition to being able to well advise you what would work best: Which, you'll probably need to narrow down your parameters a bit more than has been stated herein on this.
Plus you could talk to a few Good rigging
shops & ask them the same questions, along with getting them to splice up whatever you like. Though on something like this I'd inquire as to their history
of assembling such lines/pendants, given their critical nature. You don't want to lose a thimble at the wrong moment due to a loose splice. And you may also want a thimble which has built in retaining features. Ask the pro's.
BTW, this ain't a place to be squeemish about spending coin
Nor to quit asking questions until you're fully at ease with your knowledge base, as well as being comfortable with your solution choices. And it makes sense to have daily use pendants as well as a few reserved for storms. So that the latter don't get worn out before they're truly needed. Also, ensure that there's plenty of serious chafe protection on these, to include some of the purpose built materials for such.