Well, "good" is sort of a relative term for orks in the current metagame, but we'll see what we can do, eh?

Ork boys are ork boys. The only advice I can really offer you here is that shoota boys tend to be slightly more useful than slugga/choppa boys, if you have a choice in models. In the 12-18 inch range a shoota out-shoots a space marine, for a third the cost. In close combat, all boys mostly end up being ablative wounds for their powerklaw/bosspole nob. For the love of god, take a powerklaw/bosspole nob with your boys.

Boys in Trukks work best if you take an all-or-nothing approach. The current game environment makes the majority of vehicles into frustrating resilient shooting platforms, so your opponent can reliably be expected to have several guns capable of tearing your paper-mache, can't-shoot-for-crap death trap into so much scrap metal. Like most ork things, they are most effective when you rush in with more targets than your enemy can possibly kill. In general, that means you want everybody who is moving toward the enemy to be moving at least trukk speed so they cannot focus fire on you.

The old trukk model is comically tiny compared to the new model too, so people might complain at you. However, because it is small, you could run it as a Warbuggy proxie, which solves all sorts of problems. Warbuggies and deff-coptas, either equipped with twin-linked rokkits, are very closely matched for the much needed vehicle hunting capability in an ork army, so thats an option I guess.

Regular bikers are, point for point, the best anti-infantry shooting available in the codex, bar none. You rarely see them though, because if you want to play with just a few bikes, you could take nobs on bikes instead.

Nob bikers (a trivial proxy to claim) are easily in the top five most dangerous and resilient units in the entire game right now. (they will die to thunderwolf cavalry and assault terminators should be approached with caution.) They can use their two wounds and wide variety of equipment options to abuse the wound allocation rules in the current rule book. Tough 5, 4+ armor, and they can get 4+ feel no pain and buy an invul save if they take a painboy. It usually takes anti-vehicle rounds to hurt them, and then they get 4+ cover at all times. And taking a warboss (maybe on a bike?) can make them troops.

Personally, for 500 points, I think I would start with two units of boys +nob in trukks, some bikes to drive in front and give them a cover save, and a warboss to ride along somewhere. It has some holes, but that's what happens at 500 points.

The other way to go, if you are NOT a speed freak, is to just straight green tide it up. But for that, I really think you would want some lootas to provide cover fire from the back field, and that would require new models. Green tide, or the slight variation of green tide hiding behind a wall of killa-kans, is probably the most effective way to run orks at mid to high point values today, but playing with that many models has a negative impact on my fun.

Wow, what a lengthy and well-informed (presumably) response.

Alright, I went and picked up my old boyz and the inventory is 30 boyz, five nobs, a big mek with a shokk cannon, three bikes, and a single wartrukk. Basically the old ork assault force with some additions.

I'll take your advice when writing up a list. I like charging into melee like a twit so i'm thinking one squad of 11 sluggas+nob in a trukk, one squad 16 shootas with a nob unmounted, three nob bikers, maybe one a painboy dunno. Big mek and shokk cannon.

Of course my brother has this complete wreck of an old chimera sitting about and since he's moved across the country I may well take that and loot it, which can make for another troop transport for the shootas with some work.

Anyway, thanks for the help. I'll dig through the codex for a while and see what I can put together.