Andys are pul-mal range more if good stats and/or eth
Another option would be a griswolds armour with some Perf ame's (or whatever the rune that gives +10 str) is in it.
You could put Perf Ame in the duriels and in the helm socket (or change helm to one with some +str on it).
Lionheart gives you +25 str and other generally useful merc mods like damage and res...but honestly, assuming you're talking about ladder, you should be able to find a 4os Thresher or Great Thresher (with a lower str req) for super cheap - probably with Insight already made in it.
You can always stash the CV till the merc can wear it regularly, though honestly you're going to want to upgrade to an eth elite polearm by endgame anyway.
put a ral in the andy's to cheaply overcome the -30 fire res. Also i bought a random andy's for 5 p amethysts, i think this might be abit on the low side of the price scale for them though. My level 83 merc has 106 strength with +27 strength andy's and max is +30 which would give you 209 at 83 so just pop on some + strength armor then put the insight on. The insight then has +5 to all attributes so he should be fine if you switch it for any other armor, unless he dies then things may become annoying.
Or you could wait until you find an eth threser, eth giant threser, or great poleaxe