I didn't like the 019t at all, I got rid of mine.
If you are going to keep it, 325 chain is no good on small saws, just use 050, 3/8". A 12" bar for a 019t is best, but you can go 14" depending on the chain. I use GB bars & Stihl chain, but I don't know what is available where you are so I'd say stick with Stihl, also you can use Oregon.
OregonŽ Saw Chain, Bar and Sprocket Selector Guide