Good Magus Gestalt Pairings

Heya,

so my DM said due to story reasons we can now gestalt another class into our main one, mine being a rapier wielding dex Magus.

We're at level 15 right now and we can repick our archetypes if they fit with our gestalt class better.

So I was asking for suggestions on which class I should pick for my gestalt class!

I personally was thinking either Fighter or Wizard, the first for BaB, AC, better saves and lots of feats.

The second due to access to lvl 9 spell casting.

Thank you already for taking the time and I'm eager to read up on your responses!