Rear Mechs ::
Shimano XTR
	The XTR rear mech from Shimano is amazingly light.  It is fairly strong too.  This mech. is good for trials as it also comes in a short cage.  But the XTR is all very strong and light but you will have to pay about £80 for one.  This can be worrying when it comes to hopping on to thin objects.  Price  £79.99

Shimano 105 (road)
	A Road derailleur is good for trials as they are light and have a short cage.  Short cages are good as they are smaller so there is less chance of hitting them on something.  Though some of them are too light making them weak.  Some are also quite expensive like: DuraAce, but they guarantee a better quality.  So it may be better to buy a less expensive one. Such as: Sora or Tiagra.  Price £29.99

SRAM 9.0 SL
	SRAM 9.0SL is extremely light and strong like the XTR.  The mech is quite expensive but it can come in short cage which is a bonus.  There also come in cool graphics that will enhance the look.  These graphics include a: marble, snake skin, carbon fiber, wood and more look.  The SRAM 7.0, 9.0 and also recommended.  NOTE: That not all SRAM mechs work with Shimano shifters, and visas versa.  Price  £49.99
NOTE: Prices may vary