Well congratulations for first getting to this point, you are in a very lucky situation but unfortunately it is somewhat of a catch 22. To answer your question outright, you can log anytime in an aircraft that has a vh registration to count towards your 200 hours CPL, as well as some forms of ultralights and ballooning.
In terms of meeting the actual requirements, look to the VFR sylabus and the x-country hours are there, unless your transporting the AC to another point which you have planned up and is some distance away you dont log it.
Although I never came across any offical ruling. Sorry I would look up the offical documentation but all stuff is back in Oz
Coming home soon enough though
I did this by towing gliders for a couple of clubs and had some great times. Make sure you have a mutual understanding of what the people you work for want though, every operator knows that you are there to build your hours, but they additionally want to conserve them. As you progress in your flying skills you will be expected to cramp your circut and cut things in a little closer. This will come with time and practice.
It is important to remember that when you are doing this that you should never let the training of your instructors let slip by - you were taught everything for a reason, and when you have no one sitting there beside you telling you what to do you may find yourself you can do it better. Although better is not always safer, just remember you are not going to be top gun straight out.
Try never to get into an uncomfortable situation, you will be more greatly respected for telling some people that you are not comfortable conducting operations in conditions rather than laying on your back spead eagle to all their demands. Some operators will try and f@Łk
you over for a quick buck. Honnesty is always the best policy, discuss what and why you are uncomfortable with things, more often than not people will be happy to hand out the advice you need.
The other important factor is at the end of the day, while although you may have logged the 300 or more hours and want to sit your commercial your proceedures will be lacking slightly. If you have the money fly GA about once a month, or if not try and keep interested in the new airspace boundraies, try and backseat a nav, ferry fly anything you can get your hands on, or just plan over old flights and the basic of it all.
I wish you the best of luck and hope you have a ball of a time, stick and rudder is a lot of fun and you will fal in love with your aircraft of choise before too long.
ps. if you are looking for other private operation startings there are a couple of cattle companies that run C182 and 206's. But you have to be suited to the conditions, i'll pass on some contacts if your interested but they usually want around 180+ hours, pm me.
Bon chance...