OP, you'll likely want a mechanical keyboard for a heavy use machine.
I used membrane dome keyboards for years. The Microsoft Natural keyboards has my the ideal ergonomic layout and is extremely comfortable for typing, with the added bonus of most keys being slightly different shapes which is incredibly handy for gaming. However, these keyboards wear out after a couple of years and they don't have anti-ghosting which means you can only hold down 2 or 3 keys at once before you lose keystrokes.
I've since bought, and returned, many mechanical keyboards. I returned them because I hated the feel and kept pressing keys by accident. I did some research and the most helpful site was at the link below which has amazing technical diagrams that illustrate the "clickiness" and action of Cherry MX keyswitches.
My advice is to study these animations and decide which looks best. Try them out at a local store if possible - computer parts stores often have a Cherry MX sample board with one of each type. Then look for a keyboard with the keyswitches you want and the additional features you'd like (anti-ghosting, media keys, volume knob, macro keys).
After some research I decided on the Logitech G710+. It's expensive (regular about $150) and a little large but has Cherry MX Brown keyswitches which have a little resistance, an intermediate click as you press them, but are quieter than the Blue switches which otherwise feel the same. It has media keys and a volume knob which I use all the time. I have no need for the macro keys.
My kingdom for a Microsoft Natural keyboard with mechanical keyswitches!!!