[ATM] binoscope with achromats

[Fabio Falchi]

Dear all,
I'm considering to build a binocular telescope with two achromat refractors of about 120-130 mm diameter. I will use mainly the binos for low power wide field with 2" eyepieces.
I would like to use two 2" mirror diagonals (for each refractor) to merge the images. Is this possible?
Moreover, I don't need to go over 100x, so will f/5 achromats be up to the task or have I to choose longer focal lenght both for the chromatism and the field curvature?
Fabio Falchi