Your BEST bet is to replace the injectors. If they are the stock "pintle" style injectors, they are probably physically worn out anyway, and cleaning won't help repair the worn parts. Replace them with the newer "disc" style injectors, which perform better, don't clog as easily and last much longer. GM designed the stock injectors to be adequate for the stock turbo at stock boost levels. When you increase the size of the turbo and/or the boost level, you are moving more air than the stock injectors are capable of supplying fuel for. To put it another way: yes, you could probably "get by" with the stock injectors, but when going through the trouble of upgrading the turbo to gain performance, why would you simply want to "get by".
John at Limit Engineering is a good guy to deal with. He is the only person I have dealt with for turbos, and he has left me no reason to deal with anyone else. He can get you going with a turbo anywhere from the stock replacement mild 33 all the way up to mine, which is the largest that will fit in the stock-type housing (and also requires 50 - 55 lb injectors and 3000 stall convertor). Don't go overboard with the turbo, unless you plan to spend alot more money to get it working right.