IMO, it's very possible to pass the exam without touching any enterprise grade products, yet that will help tremendously if you can afford it, but to pass without ANY wireless practical experience is very very difficult.
I passed the CWNA PW0-100 about a year ago, during my studies, i mainly was experimenting with SOHO grade APs but also with a few semi enterprise products from vendors like Ubiquiti and Mikrotik, and also with DD-WRT firmware which is really capable and much more powerful than a "standard" SOHO firmware.
For PW0-104 you will also need some experience with 802.11n stuff, which isn't an easy topic in itself.
Don't forget to grab yourself a copy of OmniPeek Personal ver4.1 which is the last free version available before being discontinued, a supported wifi card is needed of course. A very good and FREE wireless packet analyzer like this one is indeed invaluable.
A working url here: http://www.topdownloads.net/software/omnipeek-personal_2_98561.html?hl=&ia=1
If you want to experiment with 802.1x/EAP, i recommend to download a trial ver. of Elektron Radius at http://www.periodiklabs.com/elektron , a very lightweight and capable radius server (although i didn't manage to get EAP-TLS to work, probably something is wrong with client certificates on my side).
Also don't forget to explore the wireless enterprise vendors websites and check their products, solutions, whitepapers and even some of them do provide a demo/snapshot of their solutions, ie. Aerohive provides a free online simple site survey tool, and if i recall correctly a demo of their wireless management system. That will give you with a good overview of how things in the wireless enterprise might work.
Hope that helps.