It varies and I am not saying every single one appears but a lot do. For example I can't list all of them but some of the recent ones that were HT exclusives but did come to the UK were (this is not everyone ever)
*Hand typed not copied and pasted so sorry for any errors*
- Flocked Cheshire Cat, (AIW)
- Blue zoidberg (Futurama)
- Joker in dinner suit and Harley in gown(Suicide Squad)
- Roller Derby Harley (52)
- Falcon from Civil War,
- Daredevil
- Unhooded Gwen
- Bloody Tyrese, Carol, Maggie (walking dead)
- Flocked stitch
- Chrome Darth Vader
- Reverse black flash
-Blue Aquaman (BvS)
- Rey with goggles (SWFA)
- Deathstroke unmasked (Arrow)
- Glow in the dark vault boy (Fallout)
- Glow in the dark Antman
- Glow in the dark Pumkin (NBX)
- Draco Malfoy Qudditch (HP)
- Cedric (HP)
- Bloody Jon Snow and Muddy Jon (GOT)
- Dr Who with 3D glasses
- Dr who with Fez
- Dr who with spoon
- Glow in the dark Adipose (dr who)
- Sailor Moon (w/ Moon Stick & Luna)
- Freddie with syringe fingers
- Flocked Simba (LK)
- Glow in the dark Gir
- Gold Smaug (hobbit)
- Fbi Sam and Dean, Red eyes Crowley, Charlie, Leviathan Castiel (supernatural)
- Glow in the dark Crow
- Glow in the dark Jesse (breaking bad)
- Sherlock with skull
-Glow in the dark Electro/Spiderman
- Bloody Cassidy (Preacher)
- Glittery Edward (twilight)
Yes forbidden planet is best place to check but zavvi also gets a lot. No guarantee the UK will get the Stranger things exclusives but hopefully
Check out this section on FP and always put new to old
http://www.forbiddenplanet.co.uk/9210/exclusives-ltd-editions?disp_order=6