Harman Gloss Baryta 320 is an excellent paper. It is a soft gloss, but much glossier than Gold Fibre Silk. To get anything glossier, you would be looking at RC paper or high gloss film.
There is always Epson Ultra Premium Photo Paper Glossy, and Canson has a high gloss paper. Your best bet would be sample packs from Canson-Infinty, Harman, and perhaps Hahnemühle and Ilford.
There is also Ilford Galerie Prestige Smooth High Gloss 215.