1) Alan 7005 alum. frame. Cira 2005 or so.
2) alpha Q cx 20 fork
I think the Alpha-Q is a 47mm raked fork. Nice, stiff fork, but make sure the head angle of the frame is slack enough that you have enough trail on this bike. A gravel bike still has to negotiate fast downhills, and having too little trail makes that less comfortable.
What chainrings would be well suited to this build? The cranks are DA 7800.
Also tire style and width is also foreign to me. I am thinking of 30mm front and 32/33 mm rear.
I'd ditch the 7800's and get a compact. 34/48 is good for gravel events, many of which (Tushar Crushar, etc) have some steep climbs. You'll want the 48 for road sections, although 46 would be OK with an 11.
Get the same size tires front and rear. Tire type is very event specific. You want to run slicks or file treads (like a Clement LAS) for faster gravel events where grip is not an issue, but if the event is looser with a lot of sand then an all around cyclocross tread (MXP, Grifo, etc) is more in order. Fatter tires (32mm) can be run at lower pressure, for a smoother ride on bumpy courses.
Generally, I favor tubulars for road racing, and for 'cross they're the best choice. But I think for gravel events you can consider tubeless clinchers. The reasons are that you may want to use different tires for different events, and that's easier with tubeless than tubular. Especially if you want to change the day before an event, after you see the course. Also, the ability to run lower pressures (18-24psi) is critical for cyclocross, but not for gravel events. Tubeless are still a bit iffy at those pressures, but are generally fine at the higher pressures you'll run for gravel. Finally, if you flat in a cyclocross race, you run/ride to the pit and change bikes. In a gravel race, you're self-supported. You can change a tubeless tire or put in a tube out on the road, but with a tubular, even if you carry a (bulky) spare, it won't be well-glued to the rim and you'll have to be careful the rest of the way.
Biggest downside of tubeless for gravel is the limited rim & tire selection.