I tried different combinations of W/ classes and found that the energy consumption was a little rough for me to handle. (I am normall a hack and slash player, so managing health and energy is not one of my strong points). Plus, having only 20 energy, and no energy regen pieces of armor like the other classes do, makes energy management a little rough.
At first I wanted /R for the pet and Troll unguent, but I found that the pet didn't work for me (two skill slots for a extra minor tank didn't sound right to me). Plus, being a tank, none of the bow skills would be of any use. I didn't get far enough with my w/r to get many of the other skills before I re rolled (I think level 10).
Then I thought /N for the pet (yea, kept thinking more with me would be best .../shrug not sure why)

... that didn't work either, but some of the other skills did. I still have a w/n character, but he is only level 12. I did find energy management hard, and healing was a little difficult because I never seemed to have the energy I needed to cast the spells that gave me health.
I then went /Mo. This seemed to fit my play style. Load up a constant heal (Mending when you get to post searing), and a quick healing dot (healing breeze) and I was good to go. Mostly self sufficient, but not totally able to solo. I also found that I had more room in my spell bar for warrior skills. I currently use 3 monk skills (mending, healing breeze, and resurection) and it gets me through missions with henchmen with out a problem. Plus, each of the 3 skills that I use from the /Mo secondary only use 10 energy, so even if I have cast one spell, I usually have enough energy to cast a second.
So, I definatly agree with one of the above posters, try all the secondary quests in pre searing that you can. It will give you a feel of what you can do with those classes. Find out what you like, and what fits your play style, and go for it.
If it don't work, re rolling is pretty simple, or you can just use one of your other 3 character slots to make a new character.
Hope my rambling helped.