Sard fuel reg adapter nipple question

I have a sard fuel reg, and i know the part number for the adapter i need because it seems to be universal for nissans. However, I dont know which adapter nipple i need, as that doesnt seem to be make-specific like the actual adapter is.
Does the nipple configuration relate to whether the injectors are side/top feed, or to the rail inlet diameter or?....

For reference:
http://www.perfectrun.jp/src/detail.php?pid=52006&pname=FUEL%20REGULATOR%20ADAPTER%20NIPPLE&maker=SARD&maker_id=52

depends where your reg is mounted. mine is behind the battery so i used a straight think 3/8 cant remember. but doesnt matter... just make sure nipple is the same size as the reg.

its the 2 bolt flange one top left surely ? .....so the bottom right fitting that screws into it (or else just get a 1 piece generic nissan one eh)

Frank; Yep, that's the nissan adaptor.

ok, so the nipples are all universal because they are all made by sard for the sard reg (of course)? and then it's a choice to me as to whether i need elbow or straight nipple (as mycra pretty much said)..?

I assume then from frank2's advice that either bottom right, or second from left - bottom, are the right ones (also going off the pic, and the rail i have sitting here)?

Sorry if these questions are retarded.

the nipples are not universal(tread is not nipple size)...seems you just found a small selection on that site, mine is by turbosmart.
if you are using a reg like in pic above the you dont even need one.
if you are mounting a aftermarket one say on the firewall, use which ever you think is the easiest without bending the fuel line too much. as for nipple size go with whatever size you reg nipple is.