This is what I would do for a str rogue/fighter...
A viable build, but there are other alternatives (all with one sort of trade-off or another).
It is good to have high saves, and in Swordflight you might also want Wisdom to get various special dialogue options. However, in many cases saves will not be good enough regardless, so you will also need to rely on potions, etc. to provide immunity. So you certainly could consider minimizing WIS to get more points for other abilities. Note also that you can use potions etc., to temporarily boost abilities like WIS or CHA that you typically only need in special cases.
It is perfectly possible to make use of Stealth even as a Heavy Armor-wearing STR rogue. You will get a penalty to the skill, but if it is high enough stealth can still be used, especially considering that you will also eventually get access to items boosting the skill. Not having Stealth would also limit the value of Shadowdancer's HiPS. Without HiPS available to allow you to retreat into stealth, you really need AC, so probably want to use a shield rather than 2-handed or dual-wielding fighting style. Any kind of Rogue is also going to want a way to generate Sneak Attacks, and HiPS is also good for that, though you can use Knockdown (among other options) as well.
Dual-wielding is nice for Rogues because you can get bonus Sneak Attack damage on every extra attack. You do need to be able to spare the three relevant feats though (usually requiring Fighter levels), and as indicated above the lack of a shield will hurt your defence unless you have some alternative defensive trick, like retreating into Stealth with HiPS. With HiPS and a STR build, you could indeed instead go for a 2-handed weapon, which would be a lot simpler and much more effective against Sneak/Crit-immune enemies.
I was thinking something like STR: 16, DEX 16, INT 12, weapon focus and specialization on kukris (would have to spend a feat on exotic weapons though, so I may go scimitar instead). Should I go for the shield instead of dual wielding? I was thinking of taking HiPS and amidexterity later.
Kukris are a good weapon if you can spare the extra feat (which can be a big if with dual-wielding feats also needed), since the extra crits tend to make up for the low base damage, especially so at higher levels when enhancement, elemental damage, etc. make the base damage of weapons relatively unimportant. They are also one of the few light off-hand weapon choices available to gnomes and halflings (though that seems not to be relevant here). They are however at a disadvantage against crit-immune enemies. Also Rogues can expect to do a lot of Sneak Attack damage against any foe who is not crit-immune, so have less need of additional bonus damage from crits. Scimitars would not be a good choice for dual-wielding, since not being light gives you a penalty, and again their main advantage (better crits) is less important to Sneak Attackers. Short Swords or Maces (better damage against Skeletons and others more vulnerable to blunt damage) would probably be a better choice if you do not take Exotic Proficiency. If you do take Exotic along with dual-wielding feats, you could also consider using one of the double-sided weapons (Two-bladed Swords, Dire Mace, etc), since I rewarded players who take all the numerous feats needed for those by typically making good magical versions available earlier than they would be for most other weapons.
