I'm looking to install a 4 age 20v over the winter and would like to know the best ecu/management set up to use.
What have others used.

What ever ECU you go for make sure it’s user friendly and more importantly the rolling road that you intend using is familiar with. Avoid the Weber set up as it’s not a DIY job to programe it . I have used an Emerald unit which was easy to set up and get running , Emerald are very helpful and may have a map for a similar engine?

i also have an Emerald set up by me and tuned by them, cold start and drive off like a normal car, no problem at all. After sales service excellent.

Just purchased an engine package with VEMS ecu, very clever user freindly

My 16v 4age has a omex ecu its a old one think the 300 series, have to keep alittle throttle on whilst its warming up but im fine with that. I think the newer omex units over come this

Omex would be easy choice as they have all the maps for a 4age as they supplied them for raw cars

I have an OMEX710 which controls the VVTI. It starts and runs fine regardless of temp.

Mine come with it so I didn't choose it.

my 16v 4age has an Omex 500 controlling it. It was on the car when I bought it and I've had no problems with it. Works perfectly. The 500 is no longer sold though. Current Omex model is the 600 I think. (which for information is not a drop-in replacement for the 500).

Ok, I might be being dumb but why not use the standard ECU?
I have a 16 valve 4age and am planning to use the standard ECU with that.
As you are using the 20v engine, the ECU for that should already work with throttle bodies

Best value for money MS3x, slightly better features than OMEX710.

We have fitted both MS2 and MS3 to all sorts!