Well I'll give you the 2011 theory for gearing RNG that I follow, and from there the choices will hopefully make themselves. Other people feel free to compare and contrast, but this should point you in the right direction.
Firstly, with all the Regain atmas, exact sTP figures aren't really important. Because you can't really fire non-stop between WSs without needing to run to the next worm, you will inevitably regain some random TP, borking a large portion of the point of an exact sTP set.
I mean technically if you get out a stopwatch and clock out the time it takes to fire your shots, then factor in regain, you could shave a few fractions of a second off your TP phase and WS that much faster. Let's just say I am a fan of getting the most out of my RNG whenever I'm on it, and I still haven't really bothered. Put on enough sTP to drop (or almost drop) a hit or two, and let Regain fill in the rough edges.
Anyways, with sTP not really being a hanging point, you're free to put on Snapshot/Rapid Shot/Velocity Shot bonuses when you draw, and max STR and RAtt when you shoot. Spellcast makes that a breeze, it's up on the windower site.
Then for WS, STR will be your best bet unless there are exceedingly high amounts of AGI or RAtt. RAcc is not an issue, even on Slugwinder.
As far as your specific questions, Vulcan Staff/Uther Grip is the top damage option, though there have been some very nice additions to the ranged attack boosting one hand weapon armory. Carabiner's Axe, Nguul, and Carabineer Dagger. Though I can't really envision a reason to use them... Outside of procing. Osode is legit, but I side with AF3+1 because of the Velocity Shot boost, whatever that does. Since Osode is kind of 2005, I go with the -3STR/AGI and hope that enhanced Velocity Shot is worth it. 15 RAcc never hurt nobody's Sidewinder, neither.
I'm afraid that bows have won the bow versus gun debate to me. A Vision Bow is a great way to shoot pointy sticks without tons of Trial work, and the STR bonuses from the atmas you'll want to use compliment SW better than SS as far as I can tell. Also, arrows are just easier to come by on the AH. A Trueflight build can be an extremely cheap way to do your fair share of damage, if you have an MKris or KC to build the TP.
The most important thing to do on RNG (or any DD) is to match your atmas to your playstyle. Strong Arm/Sea Daughter/Voracious Violet for SS/SW, Ultimate/Beyond/Sea Daughter (or a third MAB) for TF, or Razed Ruins/Gnarled Horn/Sea Daughter for Arching Arrow/Heavy Shot (which is apparently legit now, I haven't tried it because I don't have GH).
As for my exact gear, I go with
AF3+1/Qiqirn Collar/Fenrir/Volley Earring
AF3+1/AF3+1/Raja/Behemoth Ring with 2 STR augment
AF3/AF2/AF3+1/Areion's Gamashes (mostly cuz I don't have AF2 lol)
Aias Bonnet/Breeze Gorget/Fenrir/Triumph
AF3+1/AF3+1/Rajas/Behemoth Ring with 2 STR augment
AF3/Breeze Belt/AF3+1/Areion's Gamashes
Bersail Cap/Artemis' or Uggy Pendant/Novio/Hecate's
Osode/Seiryu's Kote/Omega Ring/Behemoth Ring with 1 MAB augment
AF3/Aquiline Belt/Denali Kecks/AF3+1
I'm sure there are some cost effective upgrades I've missed, but alas I'm not 110% gung-ho on my RNG in practice these days.
Player Total Dmg Damage % Melee Dmg Range Dmg Abil. Dmg WSkill Dmg Spell Dmg Other Dmg
Stani 295637 99.35 % 26121 12155 12606 244635 0 120
SC: Reverberation 1923 0.65 % 0 0 0 0 0 0
Total 297560 100.00 % 26121 12155 12606 244635 0 120
Player Melee Dmg Melee % Hit/Miss M.Acc % M.Low/Hi M.Avg #Crit C.Low/Hi C.Avg Crit%
Stani 26121 8.84 % 771/76 91.03 % 0/48 29.09 163 0/63 51.74 21.14 %
Player Range Dmg Range % Hit/Miss R.Acc % R.Low/Hi R.Avg #Crit C.Low/Hi C.Avg Crit%
Stani 12155 4.11 % 27/0 100.00 % 198/558 408.65 4 483/912 689.00 14.81 %
Other Magical Damage (Additional Effects and Spikes)
Player M.AE Dmg # M.AE M.AE Avg R.AE Dmg # R.AE R.AE Avg Spk.Dmg # Spike Spk.Avg
Stani 0 0 0.00 0 0 0.00 120 4 30.00
Player WSkill Dmg WSkill % Hit/Miss WS.Acc % WS.Low/Hi WS.Avg
Stani 244635 82.75 % 75/3 96.15 % 1699/3967 3261.80
- Sidewinder 244635 100.00 % 75/3 96.15 % 1699/3967 3261.80
Player Abil. Dmg Abil. % Hit/Miss A.Acc % A.Low/Hi A.Avg
Stani 12606 4.26 % 4/0 100.00 % 2285/4007 3151.50
- Barrage 12606 100.00 % 4/0 100.00 % 2285/4007 3151.50
Low acc from Sandspin, low damages from Gastric Bomb. As you can see, 96% SW land rate without even attempting to pump RAcc. Edited, Jul 3rd 2011 4:48am by tertoonetwothreefour