yeah 72 pin SIMMs are still easy to get new in the UK, Eclipse also sell them:
http://www.eclipsecomputers.com/products.aspx?cat=23&subcat=131&brand=28Mb FPM £2.29
16Mb EDO £3.47
32Mb EDO £6.99
Although bigger sticks are harder to find, like 64 and 128 so that 64Mb link is good.
Also dont forget our own best Amiga shop, Amigakit.com
32Mb for £7.99
2x 16Mb £9.99
128Mb £35
