personnel expereience, its eaiser to dye then style them, if you have the patience you can style them but its not like working with real hair, dying is complicated to but as long as you get the right dye and follow instructions its not that hard personnely if it were me i would dye the last one but if don't want to risk it you can go for the styling, just make sure if you do style everything is how you want it you only get one chance,
as for advice, take your time, use a good quailty brush, comb and brush from the inside out that way it doesn't stress or strech the fibers, when styling always make sure to have a wig head or something the equivalent there of trust me it is needed, use a bowl or the such if you don't have access to one. I have messed up more then one wig because I neglected to use a wig head, use a good quality mousse/gel the basic type you would find in fredmeyer or hottopic or the such does not work very well for fibers, you can try it but no promises, if nothing else go into your local salon and ask about it, wig styling is a common thing, I'm sure they would be more then happy to answer any questions and they might be able to help and or give you pointers if they aren't busy, and they definitely have the right mousse.
now for the dying, couple pieces of advice on that one, use a good quality dye, again hottopic dye wont work, most synthetic wigs will take a nylon dye, most people recommend using a wig dye which I agree if you have a place available but if not you could always consider using Acetate nylon dye, but if you can get wig dye go for that, always dye in a stainless steel sink unless you want your sink stained, if you don't have a stainless steel sink you can use a bucket just as well, remember whatever the dye touchs will be dyed so dress and prep accordingly, there are also a couple other methods using sharpies and fw ink here's the link
FW Ink:
http://forums.cosplay.com/showthread.php?t=57484Sharpies:
http://forums.cosplay.com/showthread.php?t=82947 here's a general FAQ about wig styling and dying
http://www.cosplay.com/showthread.php?t=132516good luck hope I was able to help you a little bit everything is to be taken with a grain of salt, this is just what my 8 years have taught me, wigs are a pain, I use my natural hair as much as possible for my cosplays/cross plays but if done right you will develop your own methods and rhymes to make it work just the way you want and it will be as good as the real thing!