Personally, I would rent an ECV from an outsid evendor versus a wheelchair....unless you are very used to pushing a WC, it can be totally exhausting (even though I know your buddies would happily push you along!)...plus it might give your a little more independence. In terms of the airport, you can request a WC curbside and then have an airport attendant bring you to the gate. (you also may be able to have a persoanl attendant (family/friend) bring you through....I have done this before, check with your airline and make sure the person who is coming along has proper ID.
My opinion, life is too short, you should definitely go and enjoy being in your happy place with good friends, even if you have to slow down a bit. (And since you run about seven speeds above everyone else, you should make out just fine!)
Good luck!
danielle