You could get by with very little, it all depends on your needs.
My wetside is just a tiny kitchen table with a $25 utility sink. This takes up about half the table, and the remaining half can hold 4 8x10" trays just barely. Similary, my dry side is another kitchen table and my enlarger takes up half. I have no problems doing what I need to do at the moment. Just think about what you'll be doing and see if there's enough room to do that. Simple.
A tall wire bookshelf should accomodate all the odd's and ends you need.