mac mini to pro equivalent?

sorry not sure if to put thin here or the mac pro section

i have a i5 2.3 2011 mac mini. its working fine and has been, but now im running out of space and ram for my projects.

my main uses are producing music and hi-res/hd movie editing, green screen stuff.

ive got an extra 750GB HD in it, 2 external 1TB drives, 16GB ram

i want to consolidate my existing wires, cables,docks, mini drives into 1, neat, machine

i know that next year a new mac pro is coming out and i'd like to get one but for now, i need more.

its not worth me spending £1900+ right now for a machine i dont plan to keep.

anyway, i need a mac pro and ive looked at bench marks and all that jazz and its giving me a headache

i just want to know, what pro i should aim for?

eg. a mac pro from 2008 quad? is a 2009 2.66 quad for £900 daylight robbery?

im not worried about it being lightning fast and cooking me breakfast just basic equivalent or better, that wont cost a bomb.

thanks