What type of vent tile for Rosemary tiles?

[Rimrogs]

I have to fit an extractor fan whilst refurbishing my dormer bathroom. From previous posts, it doesn't seem a good idea to vent through the wood cladding on the side of the dormer so I'll have to vent through the main bathroom ceiling, through the loft space and out through the pitched roof of the house. Access is fairly straight forward but I'm unsure which type of vent tile would be suitable for 40 yr old Rosemary tiles? There seem to be lead vents but the pvc vents seem to cater for more modern tiles.
Is it better to vent as horizontally as possible with a slight fall to the tile vent? Any suggestions welcomed.

 

[Alastairreid]

what about these

 

[Rimrogs]

These seem ok but apart from the colour (do they make different colours as my tiles have weathered to almost a black colour?), I haven't been able to get the size but they look as if they might do ......ant other suggestions?

 

[Alastairreid]

they come in grey brown and terracotta the only other options would be through the soffit if you have one, or through a lead slate piece which is pretty unsightly compared to the vent in the link.