Well I don't know just how much of a Brainboy I may be, but I'll gladly lend my experience with the greenskins to aid you Rasmus.
For starters, do note that I am assuming what you posted is what you have, which isn't necessarily a bad base, but certainly can, and should be improved upon... doubly so since I did the math and your total is 965.
Lets start with Bosspoles, a rather simple piece of kit to plop on or kitbash, they're easily the most important piece of Ork Wargear, especially on a squad of Trukkboyz. At first glance some people disregard their importance, but I've always found it invaluable in all my squads, especially if I'm taking Trukkmobz which are already towards the bottom rung of Orks Ld bonuses granted via Mob Rule. You also have the benefit of being able to use the Bosspole as long as the carrier is alive (which hopefully the Nobz won't get Precision Shot-ed to death or quickly KO'ed in a Challenge, both of which are common deaths of Nobz in 6th).
When it comes to Tankbustas... well many players flat out refuse to use them due to their Glory Hogs rule, which frankly was put in place to try and mitigate the squad from just taking out most if not all of a Tactical Squad in a single round of shooting. Unfortunately the Glory Hogs rule does feel in many people's opinions to go too far, and it has been claimed that tricky opponents will purposefully bait the unit with armor lying just outside their range. I personally haven't seen that, but I also really haven't touched my Tankbustas since the current codex dropped, as there are lots of Ork Anti-Tank stuff most of which feels more viable to me than Tankbustas.
That aside, in the list you posted, everything is mounted other than the Tankbustas and Burnas, meaning that even if you swap out rides for those Elites, somebody is going to get left in the dust. Unfortunately the smaller Ork units really rely on one another for support. Commonly you'll find that a single unit of Trukkboyz simply won't be enough to KO an enemy unit that has sustained a few casualties before Assaulting, this isn't because Orks are bad, but its just a fact that they rely on numbers more than anything else.
ArdBoyz are generally seen as a waste of points. They aren't always, but most of the basic Troopers guns will still negate Eavy Armor with their Ap values. Add to that the higher point cost, and you can see why they aren't super popular. Should you choose to drop that armor, you'd save more than enough points for a Warbuggy, which would be able to provide some fast AT, even if it would blow up at the drop of a hat.
The Warboss sadly can't take a Twin Big Shoota, or really replace any of his weapons, that's part of the deal when you take Mega Armor (ref pg 39 and 97 of Ork Codex). Personally in a small point game where you are relying on a lot of Trukks I'd go for a more bare bones Warboss with a Big Choppa. The Nob in the mob can issue or accept Challenges, allowing the Warboss to do what he does best which is carve through enemy Infantry, and when you take the Big Choppa you get to use the Bosses Initiative, which while being the same as a SM, is the highest Initiative Orks have. 4 Str7 attacks also isn't something to sneeze at.
The Big Mek, like the Boss can't have the Big Shoota, but it can have a regular shoota-combi weapon. Of course personally I'd go with the Burna which has the benefit of being able to fire the flamer template more than once per game, as well as being able to be a Power Weapon, but that's my personal aesthetic.
If you're really gung-ho about going with this list as is with no changes, I'll point at a Warbuggy with a twin Rokkit Launcha to fill your point value up to a full 1000. But if you drop the Tankbustas, and switch the Mek's weapons for a Burna, you'd be able to add Rams and Red Paint Jobz to each Trukk AND get a Battlewagon with a Kannon, 4 Big Shootas, and Red Paint to transport those Burnaboyz in style & about the same pace as the rest of your army, as well as getting a rather large bulletmagnet, taking priority away from the fragile Trukkboyz enhancing the overall effectiveness.
Now I know that a Wagon is a big investment when it comes to models, so I know that for a small loner army that might be too much, but in my opinion its the best way to maximize the army's overall effectiveness. This is just one opinion, and I'm sure many others will be coming shortly. Best of luck with the Orks Rasmus, welcome to the Green side.