I have a Langster and I think it's great. The frame isn't as stiff as I thought it would be. I think for 2005 the price went up to around $600, so it might not be in your price range anymore. I don't think you could mount fenders on a Langster, and with horizontal, open in the rear dropouts it'd be a pain to get the rear wheel off if you did. If you're looking for a cheap, bang around singlespeed for the road a conversion might be the way to go. You could probably find an older road bike in good shape, take all the unnecessary junk off (extra gears, shifters, deraileurs) and just put a bmx freewheel on there for way less than anything new. A normal geared chain (one with bushings) could probably handle most chainline concerns on a bmx freewheel set up. I've done it before myself, but use your judgement on it. Also, the older frame would have eyelets for racks and fenders that the Langster doesn't, plenty of tire clearance, and the old school semi horizontal, open in the front dropouts which work much better with fenders.