I bought my lexan (macrolon/polycarbonate different names, same thing) from this place
http://www.arlaplast.se. Excellent quality! They have a sales office in the UK:
Great Britain
Mr Kim Warren
Arla Plast AB
Office 6, Crown House 2
Church Row, Pershore, Worcestershire
WR10 1BH
Phone: +44 1386 561515
Fax: +44 1386 554466
Cellular: +44 7785 344 543
E-Mail: kimwarren@arlaplast.co.uk
Just a tip..