Interesting dilemma. First let me say that I highly disapprove of people changing their names - even moreso societal stigmas (real or imagined) that coerce people into feeling they need to. (I changed my own name - through adoption - but that's not the same.)
My wife changed her name over my objectiions from Xie Anmei (thanks quiet pretty) to Amy Green (Green being my surname). One of our family friends' names is "Di," which means "Earth" and I gotta say I just love that name and hope he never changes it. My favorite uncle was from Greece (a cretan). I always knew him as "Uncle Mike" and didn't know until after his death that his real name was Manolis.
That said, if you really want to change your name, you have a few distinct approaches (or a combination of them). One is to come up with an anglicized verion that sounds a bit like your Chinese name. My wife took this approach and it seems to me many do. Another approach is to translate your name as suggested by BY (the previous poster). Yet another approach adopted by some Chinese is to come up with a name they like or that they feel will project the image of themselves they want to project. So one of my friends is named simply "Scott" (except I keep calling him "Yi Hong" since that's all I ever knew him as).
I think "Wang Guoguang" is kinduva cool name that lilts off the tongue and an interesting meaning and I hope you'll consider keeping it and telling anyone who doesn't like it to go fornicate with himself. (People are going to mispronounce it, but that's not out of malice.)
Lucien King is actually pretty good - a common surname with a pretty uncommon (in the USA) and evocative first name. Maybe you could keep your last name - which is also pretty common and just change the first.
In case you're female, you could think about Gwen Wang, but I'm guessing you're male, so how about:
Gary Wang, Grayson Wang, Gerry Wang.... also Gene, George, Glenn, Greg, Geoffrey, Godfrey, Godwin and so on.
Or maybe you could go with alliteration. Keep the Wang and make the given name a W, like Willard Wang, or Windsor Wang (or William, Wyatt, Winston, Ward, etc).
Note if you call yourself William, most people will probably call you Bill, but Bill Wang is pretty good.
There are a number of really good choices, but none, I think so good as what you started with.
k