Yes, Forward of the Keel
You asked about location. Yes, forward of the keel is good. On my 23, I have the knotmeter just to the port side, and the depth tranducer just to the starboard side. Both are forward of the keel on the relatively flat section before the bow. Access is easy through the hatches in the vee berth. I agree with the opinion of using through-hull technology; no new holes if you don't have to. You only have two factory holes below water line on your 23, that's the thru-hull for the knotmeter (carry a spare plug), and for the sink/icebox...and hope you've added a proper seacock, which was not factory.