Welcome to Librarium Online!
Hi - im thinking of putting together a small 500pt army for combat patrol.
My initial list idea is:
12 Boyz (Nob w Klaw & bosspole) 112 (using the Nob as the HQ)
12 Boyz 72
12 Boyz 72
3 Killa Kans (3x Grotzooka) 135
The plan being to try and max-out on boyz, using the trukks to get them to objectives or into CC asap, and using the Kans for backup (maybe even to divert attention away from the boyz when they are enroute)
I'd drop one killa kan, and use the points to add a nob, klaw, bosspole, and a ram to one of the units of trukkboyz that don't have one. I'd also make the remaining trukk without a nob into shoota boyz instead of slugga. The rams will help you get into/through cover, and the shoota boyz will help you reach pesky distant units.
Here's my version of your list:
12 Slugga boyz w/nob, powerklaw, bosspole, trukk, ram 
12 Slugga boyz w/nob, powerklaw, bosspole, trukk 
12 Shoota boyz w/trukk 
2 Killa Kans w/grotzookas 
"Any job worth doing, is worth doing with a powerklaw."
personally i would take a squad of 20 boys incase you come up againts some mean niddy types
so have one squad of 12 in the trukk and 20 more on foot?
yeah you need some squads that are gonna stomp some 'ead's. i play speed freaks but i also have a couple of big squads to wash up afterwards, if you get what im saying