If you wanna run a signet build, I'd recommend something like this: 30/20/0/20/0
, or like this: 30/30/0/10/0
. As has been mentioned, they will NOT match the sustained DPS of S/ builds, but hey--if you wanna play Greatsword, play Greatsword.
The first build relies entirely on popping Rampage as One, Sig of Wild, and Sig of Hunt all at once for some huge spike damage. Once they drop off (~6 seconds), your DPS will, too. But you should have enough time to kill most things dead. I've had a lot of fun with the GS on this particular build.
Additionally, the second build brings your DPS up a little by allowing you to take advantage of the interrupt on GS 4 and 5, and LB 4. The interrupts add damage, which can help compensate for when your Sigs are on CD.
Now, if it's a GS playstyle you're after, then I definitely agree with the guys above--Sigs aren't really ideal. They're great for spike DPS, but that's it. I would also recommend a 20/25/0/25/0
build. Again, not top-of-the-line DPS, but still viable and fun.
One way or another, you don't need Soldier's gear. If you want some toughness go ahead and pick up Knights. But with the evade built into the AA of GS, your survivability will be rather high.
Aaaaand again, if you want to run Greatsword, run Greatsword. Peeps will tell you not to, but this is a game. If you have fun with GS, then use it.