Having just gone through this process myself, allow me to offer some suggestions. Off the cuff, I'll point you here...http://fichtenfoo.net/blog/cheap-good-airbrush/
with his thoughts and a review of a product available here...http://www.harborfreight.com/cpi/ctaf/d ... mber=95630
It's slightly more than you're looking to spend, but it's an airbrush/compressor combo for less than $100 US with all the features you're listed. You'll be hard pressed to find a better deal anywhere. When you take into consideration the amount of money you'll spend on canned air over time you're better off waiting until you have saved the extra money and buy this kit. You'll be much much happier in the end with the results, not to mention the frustration and expense you'll save yourself trying to master canned air.
I, myself, didn't buy the product I mentioned only because I didn't come upon it until after I purchased my first airbrush. Had I known of it I would have gone that direction and saved myself some cash too. In the end I bought an Iwata Revolution BCR duel action siphon-feed airbrush. http://www.iwata-medea.com/index.php/products/bcr
It's a bit pricey, but the results of airbrushing versus hand painting are worth it in my opinion. If you look here http://www.iwata-medea.com/index.php/buy_now
you'll find Canadian retailers of their products, which should lead you to ideas of prices.
If Harbor Freight isn't available in your area, or buying online isn't a viable option I'd keep these few tips in mind while you're looking.
When given the choice...
A duel action airbrush is much more versatile and offers more control than a single action airbrush, but they're also more expensive.
A gravity feed airbrush takes longer to swap between paint colors because you'll have to clean the hopper each time, but they use, and therefore waste, way less paint versus a siphon feed. (Something else to keep in mind if you're on a budget. GW's spraygun has to be a huge paint waster, which means you're forced to spend more money buying more paint. Good for GW, bad for you)!!
I recommend staying away from bargin hobby starter airbrush sets like Testors. While they are cheap you'll get unsatisfactory results, give up on airbrushing, and wish you'd spent the money on more models in the first place.
Remember, you get what you pay for, but you don't need top of the line for great results.
Bagder. Paashe, Iwata all make a number of good airbrushes and it's just a matter of digging around on the internet to find what your looking for in your price range.
I'm happy to answer any specific questions you might have before you pull the trigger on something.