Fireball Engineering makes great arms.
Personally, I wouldn't run ball joints on anything I own. I have never built a suspension system with ball joints, either. This argument could go back and forth for ever, but if you buy the FK brand Teflon heims, you will NEVER have an issue with them. They will outlast you and your bike. They are 10x stronger than those tie rod ends, I mean, ball joints. FK also sells boots for them that seal off completely. Better than ball joint boots every thought of being.
Anyways, reservoir or not, it's up to you. For riding trails, they are not necessary, whatsoever. It's a common misconception that reservoirs on ATV shocks make your shocks run cooler. The fact is, ATV shocks do not displace enough oil to generate enough heat to make a difference. ESPECIALLY front shocks. I have dyno'd shocks side by side and noticed a temperature difference less than 4 degrees F over 400 FULL strokes @ 40 SPM. Not significant enough to make any difference. The ONLY benefit to running reservoirs on ATV shocks is to keep the oil and nitrogen separate, preventing foaming of the oil, thus maintaining dampening characteristics. Again, on the dyno, I show a difference of about 16% dampening change in 400 full strokes. 90% of people wouldn't be able to distinguish the two apart.
You can buy fireball arms directly from them via their contact information under the sponsors tab here. As far as shocks go, if you're on a budget, contact Works Performance. If you don't have a budget, get a hold of Custom Axis Shocks. They make the best shocks on the market, hands down.