You can get the chips in the link posted above, but I was planning on using the Jack Daniels chips you get for smoking in BBQs. Get them for ã6 a bag when in stock in B&Q. I think they have cleared most BBQ stocks now though.
I think you could run the risk of becoming too astringent with adding chocolate malt to a Coopers Stout kit. Maybe a small amount. Adding some medium crystal isn't a bad idea either.
Cocoa nibs are the usual way to add real chocolate flavour. Make sure whatever source of cocoa you add has very...
Dark Ales:
Target: Ca:150ppm, Chl:300ppm, Sulph:100ppm, Alk as CaCo3:150ppm
add 13.7ml AMS, 7.9g Calcium Chloride, and 4.3g table salt per 25 litres results in:
Ca:150ppm, Chl:297ppm, Sulph:134ppm, Alk as CaCo3:150ppm
This has been calculated arse-about-face, but working on the assumption that your Alkalinity expressed as CaCo3 is around 250ppm, having used the calculator in the above post:
Pale Ale:
Target: Ca:200ppm, Chl:200ppm, Sulph:350ppm, Alk as CaCo3:40ppm
add 28.7ml AMS and 16.5g DWB per 25 litres...
I missed that. Here's an estimate based on what info you gave, though I haven't checked the overall Alkalinity. For pale ales, I reckon you can get away with just adding Brupaks/Murphy's DWB:
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...... Edit: I think your water is more alkaline than first thought according to the guide...
If you can't get a Calcium rating, then you can at least adjust for the Sulphate and Chloride, but it would involve some guesswork. Easier to get the Calcium figures first.