Will you let us know how it works out, Larry? I've dabbled with both Williams and Marbles sights, usually selecting a Williams front base most often, with a 3/32" diameter fiber-optic Marbles front (vs 1/16th dia).
For a contemporary look, Williams is the way to go (IMO) with either rear peeps (esp their twilight peeps; extended or non-extended), or their WGRS-family of open sights. Otherwise Lyman-style rear sights are still on the market (or fleeBay).
Also I do know the Marbles ORANGE front optic-posts are
much brighter than Williams RED front posts. But still deciding if optic GREEN front posts might be brighter / better still.
However there's no doubt the 3/32" diam are much more visible than the standard 1/16" diam.
Reason I am interested in how your HEAVY .243 works out, I'm setting up a straight .920" M10/22 in an AR-type stock with open sights to use as a .22LR AR-trainer,
but haven't decided on the front sight for that yet. 
For a rear peep will use either a Nodak or Tech Sights made specifically for the 10/22 receiver, but whether to go with a dovetail front? Or ramp and post front? Either/or, want to end up with a rabbit-ears front with AR-post in its middle.
