Guild Wars 2

I have enough karma for a full set of exotic armor. Right off the bat the whispering armor looks the best stat-wise (with precision, toughness and condition damage), but i’m not sure if I would be too squishy, or if it does not provide enough power. I’m mostly interested in Dungeon/WvW, and I’ve been mainly using D/P, D/D, and SB.

Also, is it best to mix-and-match types for more well-rounded stats?

I just hit level 80 on my Sylvari Thief and I’m a little overwhelmed and unsure where to go from here. I have about 8 gold and 115k karma. I mainly want to start running some dungeons for armor sets (although I don’t know which ones are best) and I am also interested in wvw and spvp. I’m planning on getting exotic karma armor, but am still unsure which set to get. Is it best to get every piece of the same kind (I was thinking the whispering armor with infiltration runes)?

I was thinking of running this build for dungeons: http://en.gw2codex.com/build/23810-thief-d-p-backstab-build

and something like this for pvp:
http://en.gw2codex.com/build/5225-condition-stealth

Most of my gear is level 70ish. Is it worth spending the gold on the tp for rares or exotics? My leatherworking skill is not very high (about 130).

TL;DR: Don’t know which armor to get now that I’m 80