Imaging train using ATIK 383L+ mono!!

[ronneymiguels]

Hello all,
I am planning on using ATIK 383L+ mono with EFW2 filter wheel and an OAG (not sure which one to use). I will be guiding using SBIG ST-i guide camera.

The challenge that I am facing is my back focus requirements are 55mm.

Using the ATIK 383L+ and the EFW2 the back focus is around 17mm+22mm = 39mm. I am not sure I know what is the thickness of ATIK's OAG (I believe it is 24mm). If it is indeed 24mm, then I don't suppose I will be able to use it as part of my imaging system. In that case, what are my options? Over here in the US, Orion sells a thin OAG that has a thickness of 10.5mm. That should put me at around 50mm leaving me with 5mm which I am sure I can get a spacer for.

Am I missing anything? I am not sure how to connect the Orion Thin OAG to the EFW2 and not sure what space that will take up.

Any help will be greatly appreciated.

Thanks,