My one year visa which was issued in penang ends april 5th, i would like to either get a new one from brisbane australa in february, or another from penang in March, or is it too early?

these dates suit my travel plans

March would not be to early it you wanted to get another visa then. But you would loose 90 days out the total stay you can get from the visa by doing an entry just before the visa expires.

I am not sure you would be be able to get one in Brisbane though. Restrictions that have been put on honorary Thai consulates ability to issue multiple entry visas makes it highly unlikely that would accept your application.

Penang now want proof of 400k baht in the bank or proof of income to get a multiple entry visa.

looking at the dates f the visa, you would not need one until end of August time ( allowing for a 60 day extension), but maybe that would not fit in with travel plans.