Zadok_Allen: In any case a Bard would look good on the party, since you'll need a Divinity caster dedicated to Stamina replenishment anyway. Possibly Giant Sword users as well.
The Tripleshot Crossbow also uses a lot of Stamina. It's heavy, so each shot uses up a lot, and you get extra shots (each of which uses up even more Stamina). If you have a Gadgeteer, you will likely want to take advantage of her ability to create one, so that's another character who needs it.
Zadok_Allen: Although it may be more of an exotic fun approach I actually contemplated a Lizardman Gadgeteer. That's for Stamina and a melee focus. If you'd reach Trynton on level 1 - which is kind of ridiculous of course - it would even save you 5 INT ^^
Alternatively, do the following:
1. Start with a throwaway character in that party slot. This character should be someone who is useful early on, but might not be so useful later. (A Fairy Mage who focuses on Speed and Senses is one option.)
2. Reach the Trynton fountain, the sooner the better. (Note that even level 10 will be OK for this purpose.)
3. Replace the character with a new level 1 Lizardman Gadgeteer right in front of the fountain.
4. Use the fountain for the +5 Intelligence boost.
5. Now start leveling up the Gadgeteer as normal. By the time the rest of your party has gained a level's worth of experience, your Gadgeteer will only be 1 level behind, and the gap will grow even smaller at higher levels. (In fact, the Gadgeteer will likely pass all the conventional spellcasters in your party.)
It's easy to forget about the character replace option, but this is one way it could be used. Note that creating a new Gadgeteer will give you an Omnigun, even if you don't pay for her starting equipment.