Frankly the 70-300 for the D300 is total overkill in a place like Spain and Portugal, unless you're going to photograph migrating sea birds or something. Almost everything you'll want to photograph will best be served by your wide angles or wide-medium tele zooms. Frankly, I'd just take one or the other, the F100 with the 28-105 and MAYBE the 50 for low light, or the D300 with the 16-85 lens. Too much fussing back and forth becomes a distraction. Even though the device form factor is the same, you have to think differently about how you expose with each of them - you've got to be very conscious of SBR and highlight values with the DSLR, which is not necessarily so with the F1000 (if you're using negative film).