I'm trying to retrofit my wet-weather commuter into the most reliable, repairable, zero-downtime bike possible. It's a steel road frame with carbon fork, currently outfitted with a full Campy Xenon group, and some very cheap wheels that got bought as emergency replacements when the last set failed out. Recently the bottom bracket needed replacing, and I ended up paying the LBS to do it on the spot so I could keep rolling; now I can feel the (Ahead) headset getting crunchy, so it's probably not long for this world either. All that is fine, but since it seems like I'm coming up to a fairly major service interval in this bike's life, and I'll end up having to spend some money to keep it road-worthy anyway, I'd like to buy strategically to ensure that the components I choose can be easily serviced and maintained for the foreseeable future. I have the time, inclination and equipment to do all the actual wrench work myself, so:

What components would you buy for a wet-weather commuter that's taking 200km a week of punishment all winter long? Weight is mostly unimportant in this equation, aesthetics are completely unimportant, and cost - within reason - is not specifically an object. The key focus for me is repairability and reliability: if I take care to learn what maintenance is necessary for each component and perform it faithfully - cleaning, repacking bearings, replacing wear parts, etc - I want these components to last as long as possible without major, commute-preventing downtime. I'm particularly interested in rims, hubs, bottom brackets and headsets, but all advice is good advice. What say ye, o wise and mighty?