Mtb question

y wud u want a noisy hub

I don't really get it. Its a little bit of a trend in bmx, some people will actually modify the pawls and springs in their cassete hubs to make them louder. I do love the sound of a lcicking cassete hub when I'm riding a bike, What's really weird is when you ride a bike with a freecoaster and its silent. So I guess I understand it

As for your problem I don't know as much about MTB as BMX but make sure you know how much it should cost to re-lace your wheel because some shops will over charge a ton on a wheel build. Make sure you use new spokes and nipples too.

I don't how going SS has anything to do with re-doing your wheel... but I'm pretty sure you can get single speed conversions for fairly cheap. 

what kind of bike is it?

You don't need to get a new hub. Just take your cassette apart, get the cog you want to use, then use the spacers that are in the cassette to fill the rest of the space, your just going have to get more spacers. Place the cog in the right position to get a nice chain line. You might not even need to get a tensioner if you use half-links, but a tensioner wouldn't never hurt. I'd suggest getting a bmx chain too.

Alright, well your cheaper option would be to get a SS chain tensioner, I have the axiom one, it provides ample tensioning options and is light on the wallet. But I eventually moved onto a ss hub (eastern bmx makes one for mtb's) its more expensive because you have to get your wheel laced up again, so your going to have to buy a new hub, new spokes, and a wheel build if you do that. However, since your just going ss I would go with the chain tensioner because its cheap and effective and you may eventually want to ride with gears again. And its alot easier because you just install it, remove some chain links if needed and ride on...

But if you decide to go with a ss hub, the chris king (expensive) ss hub, the hope ss, and the eastern bikes ss hubs are all very loud and effective choices, but for a cheaper option go with the axiom ss hub (gets the job done for less $$ but has a better chance at breaking quicker than the more expensive ones I listed above).

you should get a new frame with horizontal drop outs instaed aof a new hub. and about the sigle speed, go ghetto on it like i did. just get a caset and a peice of pvc pipe that fits perfectly on the hub cut it in two, slide 1 in put the cassett on put the other one on and thee stopper thing at the end so they dont slide off. make sure you center the casette before u cut the pvc so u kow what length to cut the inside pvc. doesnt cost shit and works like a charm. im still running the exact same setup.

and if u cant get a new frame just run the tensioner or get a half link.

u should post that shit on pinkbike too if u don't find what ur looking for