I too would like it to be an ingame seach interface.its not that easy to put a vendor search option in game - you will also need a possibility to LEAD the customers to the vendors they want to buy from - this might work if you have a "gate" or "recall" option to the vendor on the menu - or simple get teleported there if you wish to (Nice for FEL Vendors and Traps lol) - there should not be a auction house and the unique vendor system cancled PLS dont even think about it DEV's!
I think it could be made possible to mark a rune to the shop if you are carring one. I'm not all happy about this options.
I do believe it would be possible to use the track system for it, so you get name of the sub server, main town near and a track arrow to show the way.
Also the ingame maps could be used, carry an emty scroll and you can target it to get a map for the lokation.
It have to be ways both for mages and for non mages, I would love to see players traveling more insted of jumping from place to place
I would hate to see the interface on a webside as I want players to be ingame and not surfing a webpage standing afk ingame.