^This, learning to sharpen and keep a chain sharp will save you a lot of time and money (leaving more time to sit down and have a cold one). Looks like a pro grade straight shaft weedwacker is in the cards for you. Just about anything from the box stores will disappoint you by bogging down when you get into heavier areas and not have the power/durability to use a brush blade. Chainsaw on the other hand doesn't look like you need to go all out and spend the big bucks on something that will sit in the box after you trim everything back, a good high grade homeowner saw would probably be more than enough.
A wild ideas - I dont know the market in your area but I have seen some really nice, new, high grade stuff in some of the local pawnshops for much less than you would pay for new. Also, if you have a decent dealer locally, they may have a used selection of equipment the pro's or those with deep pockets have upgraded from. My roommate is the area sale's guy for a farm equipment chain, comes across some pretty nice used stuff from time to time.