Hi Tui, here's a cool DIY of a simple work bench. http://dreamdesigndiy.com/diy-garage-workbench/ You can make with or without the wheels too!
Hi Tui: I made my own workbench, and what I would suggest is that you put the bottom shelf high enough to put a rolling storage bin under that. Use swivel wheels on the bin. Also, I made a recessed area in the front, it's about an inch lower than the rest of the top and about 4 inches wide. For this I used 1 inch thick wood. That way, when things are rolling around, they will fall into this well instead of on the floor. Also, at one end I made a hole as wide as the well and about 4 inches long. I hung a coffee can under the hole and when I cut wood and have shavings, I sweep them into the well and down the well into the coffee can. From there, I can use the shavings and wood glue to seal any holes between the boards of the bench top. Mine is 6 feet long and 27 inches deep and I used 1 1/2 inch thick boards. Good luck.