Down-pull front mechs - Swap for top-pull?

[dbmtb]

I have the following DP front mechs. Would like to swap one of them for a similar quality top pull ideally 31,8 but 34,9 with adapter is also fine.

Deore LX
Early 90s type M550 31,8
Mid 90s type M565 34,9
Mid-00s type M570 34,9

XT
M739 31,8

WHY?