There are a lot of good quality choices for aftermarket wheels for your car. Check the FAQs for some general pointers for what to look for. The offset will change if you go with a wider wheel. That is not a constant (even the optional factory alloy wheels will often have different widths and offsets). If you are going to use the car on the track, yes, unsprung weight can have a big impact on how the car handles and performs. For a daily driver car, you will notice more change in the handling by running with a half tank of gas than you will by shaving a couple of pounds per wheel weight per corner. It's just something that has been blown way out of proportion on web boards. On the track at 90-100mph+ yes, it will make a difference, but for on the street and normal highway speeds, it would be minimal. Factory wheels are going to be top $$$ since they are the only source for them. All of the wheels we sell are O.E. quality or better and are based on actual test fitment on each vehicle so we know they will fit correctly. It all boils down to style and the look of the wheel. You can see all of the wheels we handle for your Accord here:
http://www.tirerack.com/a.jsp?a=DY6&url=/wheels/index.jsp