The ill health pensionshoul not prevent you using Collaborative Law or mediation. One of the advantages of using the Collaborative process is that you can (where needed) involve a 'Financial Neutral' - someone who can give joint information and advice about the finacial issues, and the options for spilling them - this can be very useful to make sure that you are both fully aware of any pitfalls, tax implications etc early enough to take them into account in deciding what the best way to split assets is. which in this case might be helpful to look at the options as to how your pension(s) should be treated.
In my experience, using a Collaborative process is no more (and can be less) expensive than a more 'traditional' route,and has the huge benefots taht it is geared towards you and your ex-partenr ending up with something you both agree is fair, so you can often be a bit more flexible or creative than a court would be.
I think it is likely that you will need specialist advice about the pension, and how to deal with pension sharing - As Peter says, your health will impact the pension as it could mean you recieved lower payments (becasue it has been paid early) or higher one s if you are judged to have 'imparied life' and a lower life expectancy. You wife may be entiled to a
pension share but not able to draw it for a number of years, so you will need to consider what income you will each have in the mean time, and whether any adjustments to take account of that difference is need.
You will also need to consider issues such as your respective housing needs (do your health problems mean you will have any special needs when it comes to housing?) and mortgage capacities.
Your health will also be relevent to this issue - do your helth probalems mean you are not able to work at all, or "just" that you can't work as a firefighter? If the latter, you'll need to consider what other work you might be able to do and how that impacts your earning/mortgage capacity.
It's great that you an your wife are dealing with this amicably and want to continue to do so - personally, I would suggest you try Collaboration rather than mediation as I think you will both benefot from all of the dicsussions, especially about the more complex finacial issues, being carried out with your solicitors and any finacial advisor being directly involved.
Do keep us posted