I'd just suggest you consider your lenses carefully although they are cheap so there's nothing wrong with buying and trying.

I have nothing against the 150 and your logic for considering it but the 110/2.8 and 120/4 A are extremely good lenses and may prove more useful then the 150.

The 110 has a very nice bokeh and is possibly intended as a portrait lens. I don't use mine nearly enough although I only use it on a Canon EF body anyway. I'm tempted to buy an M645 body for this lens alone. I never had one when I had an M645 1000s back it the 80's (bought it new!).

The 120 A (macro) is also an extremely good lens with extremely high levels of sharpness (even on a Canon digital body).

If you change your mind about the 80/1.9 (and I'm not saying you should, I wouldn't mind picking one up myself) then consider the 80/2.8. It is an extremely good lens and very cheap. It holds up extremely well against 35mm format lenses for resolution.

All M645 lenses will adapt to other digital bodies, such as NIkon, Canon etc, so can serve a dual purpose if you want them too so maybe this is something to consider when selecting lenses. The leaf shutter on the LS lenses can only be operated on an M645 body. I use the 120/4 A for product work (on a 5d2) with a Mirex tilt/shift adapter, see below.