I can only tell you what I have as I haven't used anything else with this set-up.
I have ULCS digital tray and handle. I like the handle - very comfy and my lock-line arms fit nicely on top. I really like the flexibility of the lock-line arms and will probably get more parts for my second arm should I decide to add a second strobe.
I have the INON WAL type 2 I think. Great so far!
I also have two INON 165 macro lenses...I have only used a single lens once so far, but expect to put a lot of time in with them in Cozumel in 9 days!!
Before you buy more lenses I would get really comfortable with what the camera itself can do, then add lenses. I added the WAL first but only because I knew that the "lens fairy" was getting me the macros! Macro is my favourite so that is my bias...the 5050 does a great job in macro and supermacro mode, but I want to explore stacked macros etc. I find that I am liking the WAL, but for the shots I like and diving I do, sometimes it is a bit limited. Mostly I use it for some shots on a dive and it sits in my pocket for the majority.
HTH