Re: vvc motors - ecu's etc
If you use the engine loom, ECU, 5AS, Relay pack, coil packs, HT leads and inlet manifold (just the top piece) from the MEMS2 VVC engine then yes the MEMS 3 engine will run just fine.
It's a lot of messing though unless you happen to have the 143 MEMS2 already fitted and need to change the engine for whatever reason.
The 160 engine has better pistons and rings, slightly different valve seats and better big end/main bearings.
If you are removing the 1.6 engine then it would be better to get the whole engine, loom, ECU etc with the MEMS3 160 VVC, at least it will all work. You are going to need to do a degree of wiring into the main loom anyway.
I recently changed my VVC engine. The engine I bought to replace it happened to be a later 160. It came with the loom, ECU and manifolds but not the other bits. To make things quicker and easier for myself I swopped all the bits off the 143 engine onto the 160 and hey presto it fired first time.
I'm not sure how different the ECU programmes are but it does feel a bit quicker than the old engine. Having said that the old one wasn't in it's first flush of youth!
If you need a PG1 gearbox with only 8000 miles on it to go with your new engine, let me know.