Aww man, Sorry to hear this.... I'm sure you'll get plenty of advice from people here on how not to let this happen again, but let's get to your issue, because of course you want to get back on that pony and keep learning.
*note - most of the damage you reported can still be ridden while being ordered or saving up some $$
All parts can be ordered from this website...there are more but I've looked and these prices are the same or better than the other sites I've viewed:
http://www.gearhead.com/oem-parts/yamaha/sport-bike.html?aribrand=YAM&s2=motorcycle
1) mirrors are easy to replace, a few screws and replace. However, now might be the time to think about replacing the mirrors with ones that actually work (LOL). Many of us have been complaining about the mirrors and only seeing elbows (without dipping our head).
2) foot pegs are very generic. you can order OEM or get some cool ones online just about any motorcycle website. I'd say they all are universal fits too.
[The above two you need to fix at least before getting on the road safety/law]
3) same as #2 ....or if you replace your front pegs, use the non-broken one for your one broken rear.
4) you can get either a new saddle (from the above website), or a saddle cover with some extra cushion (which will hold you over until either more saddles are available or you can save up some $$)
5) this may be expensive...unfortunately. The parts on the site above but not sure what you'll need without seeing it. Depending on how bad it is, you may want to consider a fender eliminator (which will fix any "fender" issues along with blinkers and license plate holder). If the break light is busted, you can replace that with OEM or get an aftermarket one (revzilla or motostarz might be a good place to start). Follow either the YZFR3 and FZ07 models as they seem to use the same light.
Doing it yourself....very possible and saving you the (whatever) $70-90 bucks an hour the dealers charge (this is primarily where the $1000+ comes from).
some part you may have to wait for....like the OEM mirrors or seat, but all the others you should be able to get right away.