The Fiio E9 will do a fine job at driving the hd650 since it is a high impedance headphone. A good dac to start out with would be a Schiit Modi for just $100 + shipping. The fiio e7k (docked into the E9) is a decent option if you want something that you can also use portably, but it will not perform as well as the Modi.
Now if you're looking for something more refined than the entry level amps and dacs, then you'll have to spend a bit more money.
@$245, the Little Dot MK III was my first desktop amp. It did a great job in driving my dt880/600 but I no longer have either of them. Lots of tube rolling options here, though I feel like the Asgard 2 is a better buy.
@$250, the Schiit Asgard 2 is a wonderful solid state amp that will power traditional dynamic headphones, orthos, and IEMs. It also has a pre-amp out feature if you wish to use powered speakers in your setup. Ultimately I returned the Asgard 2 as I preferred the Little dot MK IV SE.
@$280 (pre-built, cheaper if you DIY), the Project Sunrise 2 is a hybrid amp that gets praised by the people who use it. I have a friend that has it, and I found that its performance wasn't too far off from the Little Dot MK IV SE. Lots of tube rolling options here too.
@454, the Little Dot MK IV SE is the best amp that I've owned so far. It improves upon the MK III and I preferred it over the Asgard 2 when used with the hd600/650 and Beyer t70. The MK IV SE seemed to bring out more sub-bass than the Asgard 2, smoothed the treble a little, and made vocals sound a bit better.
There's also the Schiit Valhalla and Lyr, but I haven't heard those so I wont comment on them.
As for dacs, just stick with the Modi imo. Your money is better spent towards a amp at this point.