Which would be more accurate and why?  40 grain @ 1085 FPS or 40 grain @ 1435 FPS.

The standard velocity stuff <1100 fps is the gold standard for match ammo. I trust they've tried higher velocities and it never was as accurate.

All my experience has been similar. Aguila, CCI, eley, etc will each make several different loads with the same grain bullet. You just have to find out what your gun likes best

If you want something fast, the 17 hmr rifles are scary accurate.

You can apply general rules, like faster, heavier bullets generally are more accurate over distance.  BUT, every single gun has its own preference.  The ONLY way to know what will work best is to test them.  I usually start at the highest possible weight, and work down.  This is because the twist rate (.223/.308, etc.) usually applies a consistent limitation on performance based on the bullet length/weight.  Since this is .22, not at all with two the same weight, though the shape can matter.

And, you are talking .22, so what is the target distance?  At 25 yards, you won't really see lots of difference.  At 50, much more.  At 100, you will truly be testing the bullets/loads. 

In this case, would start at the highest speed and work down.  Your barrel length is also a factor that will skew the mfr stats.  And how accurate is the rifle, best case?  If the rifle is 2 MOA at best, your ammo won't get you better than 2" at 100 yards, no matter how fast it goes.

Personally, nothing less than a 5 shot group is statistically representative.  Eight to ten is better, if you can avoid barrel heating, which should not be an issue with .22.