Graham Slee Novo or Solo for Denon D2000?

I am new to this game so please be kind!!

I have just got my Denon D2000 and am very happy so far driving them from my iMac, iPhone, and PC at work. I am going to be using them primarily at work, and my next step to a full rig is going to be a desktop amp.

I think I have narrowed the make down to Graham Slee, because it is British (like to buy local!) and seems to go well with the Denons. However it is not clear at all to me whether it is worth the extra to get the Solo over the Novo, or whether the higher end amp would be wasted on my cans.

So is there a general guide to how much you should spend on an amp compared to the phones (and source I guess as that will be coming after)?

Has anyone heard the D2000's with both the Novo and Solo, if so which would you go for?

Are there any other amps that I am really missing out by at least not considering with the Denons? I will likely get more cans in the future so flexibility is also important.

Thanks in advance for your help guys!

Thanks for the feedback so far.

Poster one
Have you heard the solo then, or just the novo? I have no doubt the combo sounds great but I can't help but think I will always wonder how much better the solo might have been! I really should learn to be happy with what I hVe got I guess.

Poster two
yes I know I need a dac. I have access to a udac at work so will be using that most of the time (haven't heard it yet though). I had viewed this as an interim solution only though, and fully intend to get a standalone USB dac after the headamp. I was actually toying with the idea of a second hand Cyrus dac although I have heard great things about the Cambridge audio dacs.

Are there any other dacs/amps I really should be considering?