It's certainly still possible to run an Ork green tide army, and it is pretty good at low points costs.
I'd recommend you squeeze as many squads of 30 shoota boyz as you can, with at least one, but preferrably two, big meks with
KFF.
To fill up the other points, you should look at lootas or Big Gunz (the lobba being the best choice, but kannons also good if you need anti tank). If you choose big Gunz, definitely convert them using plasticard because the actual models are way too expensive.
Good luck