You don't need a 4 way manifold so never mind that one.
I'd say get the top one, i was looking at that last night, i thought it was a pretty good deal.
Your probably never going to use R402a ad such, that manifold will be fine for what your going to do.
No gauges alone work with every gas, however at BES
(Ref/AirCon > Manifolds) they have a manifold which has 'swapable' gauge dials so you can use most gases without having to buy extra gauges.
You don't need a manometer, the gauges will be fine, i'd say get a manometer or weighing station if you were replacing the charge in a unit but because it's a new/modified build then the gauges will suffice.
You should get a Vacuum Gauge though, which is sometimes called a Manometer, goto BES
(Ref/AirCon > Detectors & Gauges > Bottom Item), it's expensive but if you want to be sure then get one.