I'd like to respectfully contradict the advice iCan offered about lens choice. The cameras are fine, but the 24-70mm fitted to a camera of this type does not offer wide angle. 24-70mm is a good focal length range on a full frame or 35mm film camera - wide to short telephoto. On a "crop" sensor camera like the Pentax K series, it is equivalent to 36-105mm which is too long for many tasks, though a good portrait choice.
Despite the shrinking place of film, many colleges still insist on training students on film, and including darkroom procedures. All 35 mm SLR and rangefinder cameras will do the range of tasks you referred to, but make sure the one you choose has full manual control - exposure,AND focus.
Likewise, all DSLRs are capable of handling all these subjects and styles. There is a case for a medium format camera for landscape and portrait photography, and with lighter, faster medium format equipment coming onto the market at around the $10,000 mark with one lens included, these are an option for some people (you did say not to worry about price).
As a working pro earning a decent living from each of these areas of photography, I find that full-frame DSLRs cope perfectly well with all these challenges, and even the top-end crop-cameras are perfectly acceptable tools.