Upgrade: Speakers or Amp. mod?


I have an Onix SP3 which I love. I recently decided to have it modified with better caps etc.
However, a pair of speakers have recently been put on sale at Audiogon which are the next model up from the version I currently own and also really like.
Which upgrade would you make? Should I have the amp modified or should I upgrade the speakers?
I cannot afford to do both now.
I await your replies.
rhanechak
I found that with my last pair of speakers, every time I upgraded something upstream, they showed me more of what they could do. It was only when they were truly the weakest link in the chain that I finally upgraded the speakers.
If you buy the speakers, are you going to sell your current pair? If so, maybe you will be able have the mod as well.