Since its your money you will be spending, what do you think the weakest link in the system is? I'm sure you will get some good recommendations, but in the end, you need to play an active part in the selection. If you don't and just go by other peoples opinions, it is more likely than not that you will be disappointed with whatever you upgrade.
That said, I would recommend getting a new preamp but only if you do 2 things first. (1. Listen before you buy. 2. You need to get a really good one.) For some reason, most audiophiles tend to overlook the preamp and tend to go with more "exciting" components like an amp or speakers. The amp and speakers you have now should work ok together and I feel that you will easily get the biggest improvement with a new preamp. (I understand that some people will read this and say a speaker upgrade will yield the biggest change in the system. I agree in that you will probably notice a bigger change. Change, however, does not necessarily mean an improvement in sound quality. I think quite a few people miss that point.
In the end, I would urge you to not take recommendations from me or anyone else as your only source of info. Whatever you buy, you need to listen to it first.
That said, I would recommend getting a new preamp but only if you do 2 things first. (1. Listen before you buy. 2. You need to get a really good one.) For some reason, most audiophiles tend to overlook the preamp and tend to go with more "exciting" components like an amp or speakers. The amp and speakers you have now should work ok together and I feel that you will easily get the biggest improvement with a new preamp. (I understand that some people will read this and say a speaker upgrade will yield the biggest change in the system. I agree in that you will probably notice a bigger change. Change, however, does not necessarily mean an improvement in sound quality. I think quite a few people miss that point.
In the end, I would urge you to not take recommendations from me or anyone else as your only source of info. Whatever you buy, you need to listen to it first.