I have a little bit of Subaru background.
8 years ago I bought a Brumby (BRAT) as my first car. It had a true dual carb EA81 in it, some lift etc. I bought 27" tyres for it, bullbar rollbar etc etc. Still not content I installed a EJ22 with EFI. The task was not over my head and it would be pretty easy for me to do again.
I had trouble with the EFI a lot though and it costed me a fair bit of money for all those little things you don't think about when installing an engine. First up was the fuel lines, they need to be upgraded to EFI ready. And a fuel pump.. Then there is the old sensors on the engine, that need replacing because they throw codes. And you have to hook up custom VSS and blah blah.. Oh and don't get me started on the never ending IAC issues!
I've also had much experience with the model of car the EJ25 I have comes out of. The EFI has run me up the wall with issues so much so I am getting rid of the car because it pisses me off with drivability all the time. Half of these issues are to do with EFI programing. I can't see why it runs the way it does, but that is how Subaru programmed it and due to its age it is not re-programmable. And a aftermarket computer is $$$.
The symptoms I am having include touchy throttle (because of the IAC opens by itself as soon as the ECU detects TPS change) This means I cannot cruise at 50 to 60kph without going on and off the throttle. The engine is also plagued by a knock code which for the life of me I can't stop popping up. I've tried changing the plugs/coils/leads/fuel/knock sensor/MAP/IAC/etc. I've also logged the ECU readouts while it has done it which show no reason why it is doing it either. When this code pops up (normally when I need to accelerate to change lanes or what ever) the car loses power and pisses me off even more.
So. Now my experience with carbs.
I can, and have, stripped down and cleaned carburettors on the side of the road and been back on my way within 20 minutes. They have caused less issues than EFI has in my driving experience.
They are much easier and cheaper to setup with LPG.
They have been proven to be able to supply good power.
They can be diagnosed with eyes, fingers and ears (not computers).
When they go wrong (in my experience) they still limp you home.
Now just to let you know, I study and teach IT at VET level. Not automotive IT, but I do have a understanding of programming and how to use computers.
This all leads me to the point where I want a carburettored car again. And as much as I love the EA81 engine, it just doesn't have the potential (with the dollars I have) for the power I require. However, another Brumby with a 2.5l carb'ed engine should do it just fine.
Thank you people for your help and suggestions so far. And no the the SU, not a fan of those carbs.