新加坡采购需求：重型四层置物架，优质置物架

I'm interested in procuring two shelving units with dimensions of 6 feet in length and 6 feet in height, and the shelves should be 18 inches deep. These units will primarily store lightweight items, so they are intended for light-duty applications. Could you provide details on the available options, including materials, pricing, and any customization possibilities? Additionally, I'd appreciate information on lead times and shipping costs to ensure seamless delivery. Thank you!