Personally, I would never pay anyone for a fit. Not to demean anyone's work, but it's not rocket science. There are plenty of information resources available on the web so that you should be able to fit yourself for free. Besides, you will likely find the right setup only after some trial and error. That is to say, you might pay someone to fit you, only to find that the general "rules" they use don't give you the right setup. You might also just start riding with your local cycling club...if you ask, someone will likely help you figure out the best setup for you.

As far as your legs hurting...you might just not be in good riding shape yet. It takes a little while. Although you have done some short-distance running, cycling is a whole different thing. So you can expect to be sore at first. Of course, how you feel is based on a lot...age, height/weight, bike setup, what type of riding (flats, hills, both), diet, etc. Personally, I wouldn't be too concerned about soreness. Like someone else said above...do some stretching after your ride (10 minutes or so worth). Start with the big muscles and work to the small. Also, your seat height and cleat positioning will have a tremendous effect on what muscles you're using. Basically, you want your leg 90-95% straight when you reach the bottom of your pedal stroke. You also want your toe directly above the ball of your foot at the halfway point of your pedal stroke (when your crank is perpendicular to the ground). What pedaling style you use is up to you. Different people like to use different techniques. From everything I have read, a relatively stable heel is the best best (not dropping or raising too much in the stroke). Something that I find helps maintain a good pedal stroke is riding a bike with clips or just naked pedals...pedals that don't allow you to pull on the up-stroke (like clipless). This helps me keep in the habit of keeping constant contact with the pedal on both the down and up-stroke. (I dunno, perhaps no one else gets anything out of this, but I find it useful). Of course, I use clipless for group rides.

Take two aleve after your ride, then another 12 hours later (although advil has always worked better for me, the black-box warning and some chest discomfort have pushed me toward Aleve). Icing the affected muscle (10min on/10min off) for an hour the night after your ride would likely help you a good bit as well. Drink plenty of fluids...but not just water. Go see a sports medicine doctor if you keep having these problems.