@FoxFireOfDawn:
ooh, that pic that's definitely Shinon/Sinon ^^

and talking about where I know about the guns..
[hider=hider][img=https://warosu.org/data/biz/img/0001/70/1393875351843.jpg]

Some kids learn cars, some pokemon, etc.. I learnt the pokedex and the names of several Weapons ._.'[/hider]

According to your character I might suggest a Sniper like: (only suggestions, you can pick one if you want)
[b]Semi-automatic[/b]
[url=http://en.wikipedia.org/wiki/Barrett_M82]Barret M82[/url] (A1 or A3)
[url=http://en.wikipedia.org/wiki/Heckler_%26_Koch_PSG1]PSG1[/url]
[b]Bolt-Action[/b]
[url=http://en.wikipedia.org/wiki/PGM_H%C3%A9cate_II]PGM Hécate II[/url] (which Shinon uses in SAO2 and I picked because I started to like this sniper~)
[url=http://en.wikipedia.org/wiki/Accuracy_International_AWM]Arctic Warfare[/url] (would suggest the L115A1 or A3 used by the British Army | side fact, the longest confirmed kill has been scored with the L115A3)
[url=http://en.wikipedia.org/wiki/M24_Sniper_Weapon_System]M24[/url] (Classic American Bolt-Action Rifle)

Secondary:
maybe a [url=http://en.wikipedia.org/wiki/Glock]Glock 17 or 38[/url]
an [url=http://en.wikipedia.org/wiki/Heckler_%26_Koch_MP7]MP7[/url] is also an option
if you want a reliable and precise pistol, the [url=http://en.wikipedia.org/wiki/SIG_Sauer_P226]Sig Sauer P226 or P229[/url] would be a good one
two others would be [url=http://en.wikipedia.org/wiki/Walther_P99]P99[/url] and the [url=http://en.wikipedia.org/wiki/Browning_Hi-Power]Browning Hi-Power[/url]