Hi Guys
Just to clear up any mis-understandings...
Whilst the aluminium back cap is a handy, and often prefered upgrade, it is not necessary, and your bolt will not mystically leak if you dont buy one.
As for the UL frame, it is not significantly heavier or lighter than the PM7 frame, besides, the PM7 frame does not fit on the Rail, and the Rail frame will not fit onto the PM7. The UL frame comes with a standard board (similar to that of the DM7), it has all the same modes and adjustable settings as the stock proto board, again, upgrading your board is not a necessity, the Rail will work perfectly well with the standard board.
There are a wide range of upgrade and accessory parts you can purchase for your Rail, the best thing to do would be to contact your local DYE/Proto authorised dealer and see what they have to offer.
Thanks
Ash Chaplen
Tehcnical Support
DYE Europe