Is the "Hammer of the 6th House" needed for a mission later on, or can i just sell it??

its actually called "6th house Bell Hammer"

No quest related to those bells or hammer. You can use the hammer to bang the heads of those ash monsters and dreamer though. [img]smile.gif[/img]

Thats good news, as im standing next to creeper as we speak about to sell it, as i may be a very powerful hammer, and great fun to use, but far too heavy for my liking, and at 5000 gold peices it far too expensive not to sell :D
And i just managed to steal a Saints sheild from the enchanter in the temple, it AC is 166 Great :D

Remember that you can buy weapons back from any trader in case you need them (and provided you can remember whom you sold them to), but armor is another matter: usually the trader equips any good piece of armor you sell, and the only way to get it back is either kill him or sell a better (more expensive - not better in quality terms) item so that the worse one you need is back on sale.
Creeper doesn't play these tricks, so you can use him as a pawnbroker - should you need that thing, just give back the money.

yeah once i was doing my bind daedric armor cheat where you use a telvanni dust helm and bind a curiass and then sell it (value is 0) then buy it back and it will be bound forever. But the guy wore it and i couldn't get it back

sell hom something else that is better than te one he is wearing and he'll put it back into his inventory.