I've quit using any fly but the SimRam on South Andros' flats:
I have never had a bone refuse it. This fellow that I gave one to thinks its pretty good, too (its in the fish's mouth):
Personally, I would not wish to buck the wind all day with a 7wt. Nice on calm days, though.
Just a thought re: acquiring an 8wt. There are many good used rods on ebay. You can pick up an Orvis or Sage for less than $300. I've done it many times. Same goes for reels. English-made Orvis Battenkill Large Arbors almost always less than $200, and they are great bonefish reels. I have 3 or 4 of them.
Also, I've never had a guide ask (tell, lol) me to cast more than 50 feet.
P.S. Please let us know what your guide(s) say when you bring out that short rod.
Have a nice trip!