I'm definately ordering this bike tomorrow

https://www.bikesdirect.com/products/..._cross_cx2.htm

And it doesn't look like I'll have much options for fenders because there are no tabs down by the rear wheel. I can put a rack on it which is nice.

So what I'm wondering is if I should just use quick release fenders? That's probably not going to keep my panniers clean though.

We looking at the same bike?

I see one set of frame/fork bosses for fender or rack. You can install a set of fenders on that bike.

If you want to run both a rear rack AND fender its another problem.

Even if you want a rack and rear fender, it's a non-issue. There's no rule saying you cant put a screw through the fender stay and rack eyelet. They usually come with different length screws for this exact reason.

One threaded hole is fine for rack and fenders.
You put the heavily weighted rack stay close to the frame and on the same bolt, you then put the un-loaded fender stay.
Just get a stainless steel M5 allen bolt of suitable length so you have about 1mm of thread protruding. use a washer under the bolt head.

Certainly a non-issue, but I think you'll find the opposite order installation to be necessary. The fender will have to go on first and "inside" the rack. And be very careful that the bolt protruding on your drive side provides enough room for your smallest cog 'with the chain on it'.

This is all good news!

I have rack to the inside, fender outside. Works fine.

Set up may depend on rack and fender choices. On my VO rack the tabs hang down so p-clamps for the fenders have to go on the outside.

Hmm, it obviously must depend on rack design. With all of my racks, you would have to do some pretty serious bending to get the fender supports outside the rack in any capacity. I have PB Cascadia fenders by the way.