Welcome to the forums and congrats on the new camera.
First the 18-55mm is a very nice lens and a decent performer. Great for the low cost. If you are happy with that lens, then the DA50-200mm is an equal match. Also a very nice lens for the low cost and similar IQ to the 18-55mm. Plus it's very small and light. The quick shift focus on both these lenses is a great feature as well.
The 55-300mm is a very good mid to long zoom. Here on the forums we have a lens review data base. It's here so you can check out all the Pentax lenses.
Pentax Lens Review Database - Main Index
The DA55-300mm is reviewed here:
Pentax Lens Review Database - 55-300mm F4-5.8 ED
For a mid priced lens, it's tough to beat.
For something in a prime that would be close in length, quality and speed to your canon 85mm, I'd suggest you look at the FA77mm f1.8. It's a sweet lens.
Pentax Lens Review Database - 77mm F1.8 Limited Excellent optically, small and beautiful build quality. It can hold up against almost any lens from any brand.
If you like the idea of a macro prime to do a couple of different tasks. The DFA100mm f2.8 is a very nice lens and I'd also recommend the Sigma 105mm f2.8 Macro. But these lenses are macro first and mid length prime second. That is, they will work well as a prime but a a little slower to focus on subjects further away. it's due to the longer focus throw (amount of focus ring turn) that is something you want in a macro lens for accurate manual focus up close.