If it is often two of you, and you are planning extended trips, then you definitely want at least a Fleet. If it is going to be on full time, have you considered the flatbed model? These are way more spacious and better laid out than the slide-in and offer much more storage. The downside is they are more expensive, and you need a flatbed - but if you are getting a truck specifically for this purpose it could be an opportunity to go the flatbed route.
I've definitely considered the option of a flatbed Fleet, however, going that route feels a bit too aggressive at the moment. I want to test the waters with a Fleet/Tacoma combination. If it really works out and I ever feel like I need more space, I can always upgrade down the road. Luckily it seems like the resell value of FWC's is pretty good if I ever wanted to go that route.
Isn't the Swift only like 6" shorter than the Fleet?
The Fleet is 10" longer than the Swift. I know it doesn't sound like much, but they are able to fit so much more in this space. I was at the FWC showroom over the weekend and boy, the extra 10" is a huge difference.