1.6 ratio rockers. Do they actually hurt the geometry??

First off, changing from 1.5 to 1.6 gains you about 7% in lift. So a cam that gives you .450 lift with the 1.5 will give you .480 with 1.6. Thats .030 at max lift only, the area under the curve is increased very little. It would take more calculus than I can do in my head tonight to figure it out exactly so think of it like this: You are increasing the size of the nipple, not the whole boob. Ever hear of anyone getting a nipple-job?

The main drawback however is the increased loads on your valvetrain. The loads don't just increase by 7%. Sure, the cam and lifter faces now experience 107% of the force of the valvespring (and 107% of the mass of the valve). But thats static pressure, we are accelerating that valve back and forth so loads increase exponentially. More wear, more HP losses in the valvetrain.

Geometry is a function of the relationship between pushrod length, valve tip height, and pivot point. With shaft mounted rockers the pivot is pretty much fixed, so you either change the length of the pushrod or the valve by using a lash cap. Generally after milling heads you need shorter pushrods.

Fitting oversize valves is a time honored way to raise the valve heads relative to their seats, as you do recess the valve a little every time you do a valve job. If the seat is recessed much at all the seat shrouds the valve at low lift. You'll gain more from a good valve job than you will with fancy rockers, and maybe save enough cash to buy a set of implants (or tires).