Hi Res,
Can you be more specific i.e. do you already have an S-video signal on the Scart or are you converting RGB or composite.
How many outputs are you after?
In the UK I would check out :
www.kramerelectronics.comThey're good quality products that should have something you are after, a lot of products won't use SCART as an input (remember it is a European connector) so you will need to wire a SCART to SVHS plug (let me know if you need the pin layout).
Hope this helps.