To do the center window without drilling it , some level of wiring would typically need to be shown or the surface contact installed horizontally on the bottom/top sash. As far as getting wiring to the window, 99% of the time there's plenty of space to get wiring around the rough framing to get to the window sash itself. Usually there's some sort of trim to the extrusion as well, most sashes aren't built as a single unit.
As far as contacts, I tend to stay with Honeywell PAL-T's for surface. Not as small as others, however plenty of room for an EOLR and they have multiple wire entries and a trim cap. The PILL's have visible screws and terminal entries, so IMHO, they don't look as clean, just smaller. For recessed, I like the 944T's (diameter and magnets depending on install) and 955PST's for plungers.
I have also used GRI, Sentrol/GE, FLAIR and C+K (now Honeywell) for years. We used to use Tane for special applications, and we used somewhere around 15-20K of their reeds over 3 years. They were halfway decent, but we ended up getting more bad ones than what I'd consider acceptable, even though the percentages were very low.