20vt is a good option.
the silvertop share the same rods as the ae101 gze so it has the beefiest rods etc.
the high compression is downer for turbo but....
a fella on club 4age has been running 14.3psi for over a year now on stock compression, pistons etc
he has only done work to his exhaust side of things. and with that he's making 220kw atw,!!
but even that pushing it. a silvertop will handle 7-9 psi all day long on stock internals.... not saying from experience but from lots and lots of research.
and that will give you approx 150rwkw. td04 would be a good turbo.
the 16v is more torquey. but the silvertop isn't... although if you go aftermarket ecu and have the vvt switch on earlier you will make the power and more torque a lot earlier on.
my thoughts are.....
16v is more simple and easier... no real benefit over the 20v.
20v more difficult but newer technologies and still just as much potential as a 16v.
another thing to consider is that ARIAS make aftermarket low compression pistons for the 20v......