Raven Audio and Beyond...

The Raven will be a huge, massive upgrade to what you have now, with virtually no downsides. It will be plenty of power, not enough to party loud or blast yourself out of the room, but with that caveat still definitely plenty of power, not at all something you are wishing every day for more.

Your plan for system development is music to my ears. This is basically the way I have done it, certainly the way I started. One major component every year or three. No baby steps, each one a major improvement, the kind of thing many audiophiles would say is out of balance or not matched. So? If you are building a system the smart way to do it is great strides. This means there will be times you have something that seems way out of line with the rest of your system. A Raven will tower over everything you have right now. But then over time as you gradually improve speakers, source, cables etc it will come more and more into balance.

The one time I didn't do that was interestingly enough my current Blackhawk. Before that I had a Melody I880 integrated. The Blackhawk certainly is better. But not great strides better. Incrementally. Worth it, but kind of a place holder. What you want do is avoid incremental improvement, at least in components. In tweaks, fine. Incremental tweaks really add up. Add Pods, elevators, HFT, Podiums, etc they all combine to make something really special. With components though it is better to make a significant commitment with each one. This is how you build for the long term.

Something to consider in picking a speaker first. There are a lot of amps, yes. Depending on your choice of speaker however you may wind up with virtually zero amps to choose from. Or very poor choices. Search around for all the time and trouble people have had taking this approach. If all you do is consider the speaker then at least be intelligent about it and exclude from consideration anything below about 92dB, as anything below this and you quickly run into a situation where only 100+ watt amps will do.

The Raven Blackhawk is a truly fine amp. As it turns out, a lot of the very best sounding amps are even lower power. There are some pretty fine amps in the 50-60 watt range as well. Above there and it gets real hard (read, expensive) real fast to find quality sound in 100 watt and up amps. Real hard. A lot of us would say impossible. No matter how much money you have to throw at it.

Being on a budget it is simply not responsible to say pick a speaker without making this tradeoff as clear as can be. 

Stick with speakers in the mid-90's and up sensitivity wise, and you will find it very easy (read, affordable) to find a truly high quality amp to drive them. 

I would say without a doubt given your current setup the Raven with your current speakers will sound a lot better than the other way around doing the speaker first. Way better. Like no contest.

Yep, those are the ones. If you want I will be happy to provide contact info for ALL those here at Chuxpona21™ who heard them. 

Your Dynaudio speakers are only 85dB sensitivity. The Raven is an outstanding amp. I have The Blackhawk, and would wholeheartedly recommend either Nighthawk or Blackhawk as your "end game" amp. 

Which to do first, hard to say that it matters. Your Dynaudio are only 85dB sensitivity, which is very low to be using with the 20W Raven. HOWEVER, we had some 87dB speakers here and running with my Blackhawk in my room (bigger than yours) they CAME ALIVE with the Blackhawk! We had no problem reaching a very satisfying volume level. So if you do decide to get the amp first you can look on the bright side and finally hear the Dynaudio sound their very best. Just bearing in mind having to crank the volume up a lot and not listen to them "loud" loud but just pleasingly loud, if you get my drift.

Then in terms of speakers if you can match the Raven up with Tekton Double Impact, now you are talking some incredible good sound for very reasonable money. 

Downside of doing speakers first is like this. The Raven will make your current speakers sound fantastic. But the DI will not make your amp sound fantastic, or anything else for that matter, they will instead let you hear exactly what they sound like. Which may not be that good. But a lot of people hear the sound coming out of the speakers, and credit (or blame) the speakers. 

So brace yourself for the reality that your big speaker upgrade (if it is to good speakers like Tekton) reveals as many faults as strengths. I have seen it before, people blame the speakers for the stuff connected to the speakers.

Also the backlog on a Raven is way less than the waiting list on Tekton. So you can get the Raven now, then order the DI and by the time they are ready you will be too?

The only other amp I could recommend in your situation would be the Decware integrated. But Steve's wait list is a year+, and his amp is low power and so absolutely needs you to have the high sensitivity speakers first.