Choice Specs all in all, is the superior choice for a Rain Sweeper variant of Jellicent. As for your Move issue, it isn't really an issue. Do what Kyogre does, and run both Water Spout and Surf/Hydro Pump in the same Moveset. Also, Jellicent is way too slow to run Choice Scarf, which Ferrothorn can relate by running Choice Bànd. Also, Smogon suggests running both those Moves in the Specs Variant anyway, just in case you needed more proof.