Mercenary? Merchant? Werewolf? Maybe an offshoot of the Mage guild or the Undaunted?
Complete daily quests that would pertain to the guild's chosen profession and earn your guild "Honor" or "Recognition" points that would then be used to purchase items such as a guild house, furniture and possibly crafting stations. You don't like the direction you chose? Spend a few points and choose another in thirty days. Vendors should remain gold based as this is useful towards controlling the economy and besides your paying for the services so it makes sense. These quests would be up to the individual members to complete and balanced so that a guild maxed in members doesn't have a severe advantage over one with fifty. This would need to be something unlike anything else in the game atm, difficult and unachievable in a week, maybe even a couple of months

. Just a thought what do you all think?