here's a nice crit pistol build that branches into a pistol/snipe build mid game
starting build:
STR 6
DEX 8
AGI 7
CON 3
PER 10
WIL 3
INT 3
Then all points into guns, throwing, (you will be using grenades for cc quite a lot, mostly flashbangs and emps) dodge, evasion and stealth (because you have no CON) +3 more for whatever you want. I normally go with hacking and lockpicking because I don't like missing stuff and traps because it's nice to disarm them. Stealth coupled with high-ish AGI gives you fantastic alphastrike and the DEX/AGI combo gives you good initiative if you get caught out.
development:
First feats will be aimed shot and gunslinger (this is nice at the start but quite important later on) Make sure you max those first 5 skills EVERY LEVEL, or your build will fall to pieces - though you can stop with throwing at 80ish. Thrid feat will be recklessness. Put your first base point into perception and the next 3 into AGI for blitz later on. You can put that first point into INT if you like so that you don't lose hacking points, but personally I feel that this is a waste. Put your last 2 points into PER for a very welcome boost to guns at higher levels. Fourth feat is steadfast aim (absolutely essential), fifth is ambush (this is a crit build after all) 6th kneecap shot, 7th sharpshooter, 8th snipe, 9th critical power (huge powerspike here, especially when used with sharpshooter) 10th is rapid fire and 11th is blitz. From there you can choose what feats you want but I normally go with grenadier and nimble.
gear:
Grab a 7.62 ASAP. hammerer/hawker doesn't matter, just get as far away as possible from that 5mm piece of trash. it's great against the rats but anyone with DT not so much. This will carry you to junkyard. At junkyard, grab a .44 - there's a thug in the shack by the slums that always carries one. remember how i said gunslinger would be useful later? well gunslinger+8DEX will give the .44 an AP cost of 25, so you can fire that beast twice a turn. when you get snipe you should be at rail crossing, grab the druganov so you can open combat by deleting one guy with a snipe and another with an aimed shot. for armour just go leather black overcoat -> tac vest with black overcoat. preferably insulated as they have the lowest armour penalty. get tabi boots as soon as you see them, as long as they're not aluminized (they help a lot with kiting). and don't forget smart goggles for the bonus damage to special attacks. look for high frequency shields to defend against high-damage attacks (and coil spiders, seriously i hate those things so much) That's pretty much it for this build. And always keep by some W2C rounds for the tin cans.