Ia a good amp more important than a good DAC?

I would rather have a great amp. You can get such good sound out of the lesser expensive DACs than you can out of a less expensive amp. Personally that is what I think after having experimented both ways. Ideally you would have good stuff for both, but it seems like now you can get super sounding digital for less money than super sounding amplification. Others might disagree, but that is what I've found having gone both ways. I could no matter what I tried get my bedroom system to sound great until I ponied up for a top notch integrated. I don't think either you have to spend big bucks on either to get fantastic sound. Ultimately I think pairing the right amp to the right speakers is the most critical decision one can make in a system.

Sink your real money in the components which have the greatest prospect for longevity. Speakers and amp (integrated) if carefully chosen will last a long time. Sources seem to change more often as do formats and good ones are fairly easy to find and can be fairly inexpensive. Over the long haul, if you are careful in the amp/speaker selection, you can continue to improve your overall system by increasing the quality of your sources. That is what I would do anyway.

I agree with that posters above.

I remember running an entry-level AMC transport and DAC with my new Audio Space tube integrated and Triangle Titus ES monitors. It was just because I upgraded in that order--amp, speakers then source. I had thought the system was OK until I got the new downstream gear, but after that awww... I pretty much stopped listening, even for lullabies. The source turned out to be just too limited once I could hear it properly.

Listen to your present source with the amp you plan to buy, then try the other way round (new DAC and current amp). See which setup you think you'll be able to live with most easily while you save for the second piece.

I think you are right to try to make the choice, BTW, instead of spreading the money over two pieces of gear. It makes sense to upgrade big, not often.

I am in the source first camp.
You amp cannot fix what is not right upstream.