Buddy let me explain a bit further. The Tiger comfort depends on 2 things. My Tiger was a bit rough owing to the MT tyres I installed and stock suspension.
If you keep your tyre size 265/70/15 with AT or HT and as long as your suspension is good added with perhaps two sandbags in the back, your ride comfort would be much better. Depending on how many pattas you have on the rear kamani will also make a difference.
Mileage will vary also according to tyre choice. I had gone for a 31/10.5/15 MT tyre which is why my ride comfort was compromised. If you have your mind set on a dalla, then make sure you have regular tyres for motorway and daily driving. If you want the look and if you go offroading regularly, then also keep a set of MTs along with the ATs/HTs (go for ATs, HTs are lame imho).
The IronMan suspension will make your ride even smoother, there is a significant difference between this and stock suspension. You will also get a bit of lift with the IronMan set up.
Lastly, I would recommend for you to go for a Surf with 1KZTE. The Hilux no matter how many adjustments you make at the end of the day is a rough n tough work horse. The MT tyres you can always add on when you need to.
Your lower back will hurt on the long drives, this i tell you from experience. I took my family to Naran from Islamabad and by the end my back was killing me! Despite this, its a personal preference, I would STILL always go for a Tiger, so much so that I might get another one now