Welcome to airsoft. My advice would be go out to a game before you buy a gun. Meet the crowd ask some questions, spectate some games. Perhaps see if someone has a rental for you (post looking for rental in the game thread). You may see a gun there that much better suits the field or the way you want to play. And get AV'd first, generally you'll find better prices here than out there, hate to say it but be patient.
G&G doesn't make a bad gun but I would highly recommend you stay away from G&G Top Tech because they have that very unsatisfying half-baked proprietary blow back system. If you want a great starter M4 that can grow with you (instead of having to buy another one later), look into the King Arms M4's. The King Arms M4 is an extremely good value for the money; high quality full metal externals, realistic trades, and solid "Mauri compatible" (easily upgraded) internals that perform well out of the box.
Don't be overly concerned with gear and clothes right off the hop. I, like most people had a budget when I started and one of my biggest regrets was spending a bunch of that budget on gear before I really needed it. All you need to play is eye protection, a gun w/ battery & charger, a high cap and bb's. No sense in having a bunch of gear just to look the part, don't waste your money on cheap crap only to regret it down the road. You can put together a contractor loadout for incredibly cheap. A pair of cargos, a regular collared shirt or sweater and a $25 chest rig. You never know what team you might want to join down the road, they may run something completely different from what you have and you'll be forced to buy a whole new loadout. Spend as much as you can right now on good quality essentials, your gun, eye protection and some good boots, you won't regret it. Get some quality full seal eye protection that's comfortable to wear and has a thermal lens that won't fog on you. Don't forget about those teeth, a mesh mask will do the trick. Get a good programable smart charger that does nickel, lipo and life batteries, they're not sexy and they're often overlooked but they're important to have. This will give you maximum performance and life span form your batteries and will last you for years to come. Get a nice set of boots: Magnum, Danners, Original Swat etc. your feet and ankles will thank you. When it comes to boots try before you buy, everyone's feet are different. And it sounds like you got the right idea about not getting a cheap gun. ***Far better to spend now on a gun now that will grow with you rather than spend now AND spend later. Cheaper guns and guns with plastic receivers tend not to hold their value and resale is low. In this country you're far better off getting a gun with a good quality metal receiver with your original purchase as they're expensive and hard to find later.***
Oh yeah, and invest in a nice set of rain gear. But living in BC I'm sure you already have some.
***this thread may interest you http://www.airsoftcanada.com/showthread.php?t=131547