Shocks don't really do much for body lean, not their job.
With the tires you're running, you will be limited in performance anyway so I wouldn't suggest Bilsteins.
Firmfeel sells bigger torsion bars and front/rear sway bars. But nothing is cheap, you could easily exceed the purchase price of the Doba with just new T bars, sway bars and Bilsteins. But with those the handling is done (except for better tires).
I'll disagree with the tire statement. I put Bilstein's on my Dart with 205/75/14 tires and I noticed a night and day difference. On the freeway, the car wasn't pitching as if I was sailing the seven seas. Although, I will agree that sway-bars and/or stiffer springs would better suite reducing sway.
Again, if it's a car he plans on cruising around with for a long while, I say go for some mild upgrades. Who cares if you've got more money into it? Some minor upgrades will make the car so much more enjoyable.
