My understanding is that to get real choice in CFL you will need to go with separate ballasts and tubes.

There are no rules. Just go with what you like. I like 5000K, but a good CRI paramount for me.

There are plenty of "real choices" in common CFLs with integrated ballasts too.

For most indoor lighting I'm accustomed to 2700K that matches the look of incandescent lighting. Occasionally the whiter 3500K ("bright white" or "neutral") helps to prevent whites and light greys from looking dingy or yellowish, especially when the bulbs are covered by off-white lampshades.

5000K daylight bulbs work well in kitchens with white cabinets, or in basements, garages, and recreation rooms where you want bright, outdoor-like light where there isn't much natural sunlight from windows. The key is that 5000K bulbs need to be bright (or use lots of lower-wattage bulbs) to acheive the "daylight" effect; bright 5000K light can lend a stunning sunlight-like feel to dark indoor rooms, but dim 5000K light looks like a gloomy, overcast, cloudy day, as if heavy rain was three minutes away.

My preference would be for 5000K that tolerate a lot of on-off cycles. I've looked on a lot of shelves and racks in stores that I frequent and I have yet to see a integrated 5000K CFL of any type.

5000 or 5500K CFLs are commonly available. Here's one I bought a while back. You can also get brighter ones. CRI is supposed to be 91.

Here is a link that might be useful: ALZO 5500k CFL

What store did you buy them in? How well have they performed? Do you use them in an application with frequent switching?

I see that they can not be used in enclosed luminaires or base-down in semi-enclosed. The producer's web site does not say if they can be used outdoors.

I bought them through Amazon. They are in a closet which I wanted to light brightly -- looks pretty stark compared to the incandescent lights in the adjacent room. They seem just as when new but they don't get switched on much, maybe two or three cycles a day. I don't think you will get much life out of any CFL in a luminary that lets it get hot, exacerbated by higher wattage.

I tend to prefer brighter lighting, because dim lighting drives me nuts... but that's just me! :)