I can't answer your question as to the difference between
3 and 4 way FEL valves (but I think that it may have to do
with being able to lift/drop and curl/uncurl at the same
time, which I can do with the 4 way valve)
I got the LA302 on my B7500HST and it came with the
4 way valve; I don't recall the dealer offering me a choice,
so my guess is that you'll get the 4 way valve.