In our large Sixth Form College, we currently use AQA; C1 in January, C2 and D1 or M1 in June, C3 in January, C4 and S1, D2 or M2 in June for single mathematicians. We tried doing the application unit in January instead of C1 thinking that C1 and C2 together would reinforce each other - but it didn't work!
For Further Maths, (timetabled as two full subjects) it is C1 and C2 in January, D1, S1, M1 and FP1 in June, then C3, C4 and an application (M2, D2, or S2, depending on what the majority would benefit from - we only offer one of them) in January, with FP2, FP3 and FP4 in June.
We also offer Further Maths AS in the Upper Sixth: FP1 in January, another FP (currently FP2) and S2 in June.
These work for us!
However, the specifications are changing, not sure when, and it is unclear what the new requirements will be. I hope you don't have to teach the old spec. for one cycle and then have to change. Having personally been through several different specifications and two exam boards since Curriculum 2000, I wouldn't wish that on you or anyone!
PS - We're building up our GeoGebra resources for AL Maths, so just get in touch!