Here are my plans. Keep in mind that I'm a minimalist and try to keep things in the category of "making the rifle better", and don't subsrcibe to hanging a bunch of crap off my weapons:
0) Free-float the hand guard. I see this as the must-have upgrade because it helps the accuracy of the rifle. It involves buying the conversion barrel nut for $24 (available from someone here), and the Yankee-Hill Machine rifle-length smooth forearm ($120). This forearm is 2-inches longer than the stock handguard, and will therefiore increase the sight radius, making the rifle even more accurate than merely floating the handguard.
1) Magpul CTR stock - because it comes with a handly place to mount a QD sling swivel.
2) Magpul MBUIS flip-up sight set. This allows you to fold the sights down when you're using optics.
3) Primary Arms MicroDot red-dot site ($89). I have one of these on both of my big ARs, and it's a tough, inexpensive little sight.
4) A decent 2-point sling. Hven't made up my mind yet, but I have Magpul MS2's on my big ARs.
Vertical foreward grips can be problematic because they can inadvertantly teach you improper grip technique. In fact, I don't think a .22 rifle needs a forward grip at all because there's no recoil, and therefore holding it on target is much easier than with a bigger-bore weapon.
I think bipods are just silly. Learn to shoot offhand. That's where all the skill is. Anyone can shoot reasonably well from the bench/bipod.