A few years ago I bought some Glycin & a Nelsons toner kit from PF & it arrived promptly & I didn't have to pay VAT or duties when the package arrived at my home. Importing items from outside the EU is hit & miss with regard to VAT, sometimes you get charged & sometimes you don't, but as I understand it if the value of the goods is below £18 you shouldn't get charged VAT.
I would second Bob's suggestion to mix your own & all you would need is a 100g of Glycin from PF which will enable you to mix up several different Glycin formulas. The rest of the chemicals could be bought from say Silverprint.
Andrew