Very high end? Depends on what you mean by that.
I don't see nearly the selection of rum at the $40-$60 750ml price point as I do whiskey, bourbon and scotch. I'm not sure how much of it there is up around here as there's undoubtedly more demand for whiskey and a bigger market looking for the high end stuff.
Since you liked the Shellback, I'm wondering if you prefer a sweeter rum rather than a dryer one?
These are my two favs:
Plantation 20th Anniversary
http://www.masterofmalt.com/rum/plantation/plantation-xo-barbados-20th-anniversary-rum/
Kirk & Sweeney 12 yr
http://therumhowlerblog.wordpress.com/rum-reviews/dark-rums/kirk-and-sweeney-12-year-rum/
Those links are just what pooped up in google, so I'm not saying that I agree or disagree with the opinions that are stated.
Anyway, both have cork stoppers, both have cool bottles with etching instead of labels (my Plantation bottle is different than the one they are using now as I got mine a few years ago) but most importantly, I find both to be very enjoyable, sweet-ish sugar cane style rums. I give the nod to the Kirk & Sweeney, but only by a nose.
The complexity of the flavors is what sets these apart from other, cheaper gold rums. It's very noticeable even when mixed with Coke.
I believe that the K & S is around $30 and I believe I paid $40 for the Plantation - both in 750ml bottles.
If you're looking higher end than that, I can't help you. I just don't have any experience with them.