Pre, I usually buy at Alexan GD124 kaya nga lng minsan lng sila nagkaka-stock so make sure you call them every now and then. So pag-may stock sila I usually buy 4 to 6 of them.
If i need a bigger enclosure than the Alexans GD124, I order na at epektos.com (see http://epektos.com/product/452eb59a-980f-4bb6-86cf-bc81975138b9.aspx).
I'm still looking for a cheaper option though.
hope that helps.