What kind of Upsampler and Jitter reducer??

Hi there,

I was wondering if anyone can make a recommendation for something that can upsample a digital stream (16/44.1), and also clean up jitter.

I have been looking at the Monarchy DIP Upsampler, but considering I can't find anything else to compare it too, I would feel better hearing what my options are before purchasing anything...

I have a very tight budget, so the price needs to stay below $300.

All comments and suggestions are welcome, and thanks in advance for the help!

Setup where the Upsampler would be added:
Airport Express -->(Upsampler added here)--> Emotiva XDA-1 DAC --> Sony V444ES Receiver --> B&K ST125.2 Amp --> Klipsch RP-5 fronts
cambridge audio dac magic plus
Not alot out on it yet, but Audio-Gd has a new piece out
Di-DSP 3.1, looks very promising.
I've ordered one yesterday.
Where can you purchase the Audio-Gd unit?

Please do report back on the Audio-GD. They do seem to have quite the following, especially from the HeadFi crowd.
Thanks everyone for your input, that is very helpful. Whenever I pick something up I'll be sure to share my findings!