http://www.vtx-parts.com/VTX-Parts.com-Pair_Valve_Cover_Custom_Honda_VTX-1300_%20&_VTX-1800.htmThese look great being highly polished stainless (not that they can be seen under the tank) and are quick and easy to fit as they don't require the reed valves to be removed, this also makes replacing the original parts easy if ever required, even a plug for the airbox was provided.
The price was very reasonable at $15.99 plus $7.00 shipping to the UK, delivery was in less than a week.
I found the change in exhaust note to be quite dramatic, with the sharper edged 'crack' of the uncombusted fuel buring in the pipes removed my V&H pipes seems deeper and smoother, while the overall dB being produced has probably not changed the pipes seem subjectively quieter at tickover and low revs and are, IMHO, easier on the ears when riding. However the throaty roar is still there and the chuckle of mini backfires is still present on firm deceleration.
Obviously it's very much a matter of taste whether you prefer the smoothed sound of an engine with the pair valves removed or the more aggressive sound with the extra air bing introduced. But if you do decide to lose the valve these plates are a cheap and easy way to do it properly.