lap seat belts inertia or standard ?

hi all im a defender virgin and im looking to add rear bench seats (320737)
and belts either standard (ba187) or inertia (ba187a)
i have a question about the belts , i have seen a lot of lap and inertia lap belts on ebay a lot cheaper .. anybody used or tried the belts .....thanks

Which way are your bench seats facing ?

Side ways - forwards or backwards ?

"Seat belts are not designed to be used with side-facing seats and, although it is not illegal to use them, with or without seat belts, we would not advise that they are used. Seat belts on these seats may help to prevent the wearer being thrown around the vehicle or from being ejected, but in a frontal crash they can increase injury risk by subjecting vulnerable parts of the body to higher loads than belts used on forward facing seats. Our advice is that passengers are safest in a forward or rearward facing seat equipped with a lap belt or, preferably, a three-point belt. Any seat belts fitted must comply with the latest British or European standards and be marked accordingly with either the 'e', 'E' or BS 'Kitemark'. The seat belt anchorage points should also be designed so that they will be capable of withstanding the high forces of an impact."

From the department of transport regarding seatbelts and sidefacing seats.

thats great info thanks........
its the side facing bench seats i have ordered 2..
and ill not bother with the belts as its not a mot fail is it ?