I've found 2 very good bike stores both with excellent deals on a different bike each and I'm now ready to buy one.

What are some good tips, tactics and best practices for negotating price for the bike and gear? Should I push for changes to the components if they aren't exactly what I would like? Can I negotiate on warranty, tune ups, etc.?

I'll need a pair of shoes (never used or had any), pedals, a small bike tire pump and a computer. I may also get full length tights as it's autumn here and cold in the mornings and possibly a jacket, preferrably with a stripe cars can see when it gets dark out. I have a helmet, gloves and cycling shorts already.

Any other things to cover?