Supplies:
bicarbonate of soda - tubs from supermarket, like supacook
citric acid - some old fashioned chemists sell it, as do some homebrew shops, but better off getting it from soapmakers
floral water - hydrosol is expensive, I generally get my rose or lavender water from boots, or witch hazel from the chemist
botanicals - soapmakers
table confetti - haberdashers, tescos
ice cube trays, chocolate box layers, small jelly or chocolate moulds, egg cups, even silver trays that you make your mince pies in, or get professional bath bomb moulds from soapsuppliers.
The problem with getting stuff from soap makers is:
1. they usually charge £6 p&p.
2. you usually have to buy large quantities
try soaposh or justsoap