As clock boy stated the height is most important. After about 30 years sitting at the wrong workbench height for me I developed Spondylitis and it put an end to my watch/ clockmaking, I don't want anyone to end up like me. Make sure it is going to be big enough for what you want, you can never have a work bench that is to big because you will begin to use up the space. I would think hard and take a look on this forum some have taken photos of their place of work and posted them. If I were in your shoes I would have a bench made for me, if you are a handy man you could make your own. Light is also very important, what type of lighting are you thinking of. As you said draw space is another, what do you intend to keep in them and will they be big enough for all you want to fit in them. Shelves are good to have I had them all around, what didn't go in draws went on the shelves. If you have a lathe and cleaning machine where are they going to go you need separate space for both. Make sure when you sit you have plenty of leg space, you don't want to be sitting with your knees rubbing the work bench.