Wheelchair users-- making caster forks tallers with small casters?

Hi,

Here's my dilemma:

I use a manual wheelchair part time for a chronic illness. I'd like to get 26" rear wheels so my arms will need less help pushing, but I'd also like to reduce my front casters down to 4" light up scooter wheels (they are currently 6"). However, I don't want to tip forward too much, and I actually do need the footrests to stay on.

So assuming I only need my current caster assemblies or forks to be about 2" taller (8" from the bend to where the wheel bolts through, total), how do I do that? Should I just use one of the 8" caster forks with a 4" wheel? Would there be any problems with that? Are there any other solutions?

Thanks!

<3