Am I wacky or does he have the jack pad sitting on the starter? That would be a real good way to break the rear engine case.
I don't know what kind of filters those are but I am running K&N RU-1770's which look similar. The filters in the picture may not be K&N's because they have chrome tops. The owner of that bike may have found some chrome disks and glued them on. Also, he took his stock bearclaw and cut out holes for his filters. This leads me to believe those filters are not RU-1770's because I really don't have room for much of a bearclaw. The RU-1770's work because they have a 20 degree angle on the flange and you mount them angled forward so your knee doesn't hit them when you are riding.
Here is a pic of my bike:
The bottle you see is the coolant overflow jug, when you put on individual air filters you will have to devise a new coolant bottle. You will also have to remove the stock air intake system.
None of this is very hard to do, you just need to find a mechanically inclined buddy to help you out locally.
Bottles can be found at places like JEGS:
Catch Cans & Expansion Tanks
Or Summit:
Link Removed
As far as the Nitrous goes... those setups can also be found at JEGS or Summit. If you have a local high performance car shop that would be a good place to visit. I have to think that most of those NOS systems are a custom install. You'll probably blow your motor up if you actually use it. It looks evil though, doesn't it
This may be the kit in your picture:
NOS Sneeky Pete Hidden Nitrous System - JEGS
It says it's for a carburetor however, so the one in your pic may not be hook ed up or it may be a custom install made up of individual parts.