I, like you, am not happy with the factory ejector button. The New Vaqueros come with a crescent button that you can order and it's a drop in installation. However, still too abbreviated for my taste and doesn't tuck up tight against the barrel when at rest.
A bullseye rod I think you will find ideal but may give you holster fitting issues. There's other options:
For about $35 you can get a rod with 'Colt style' crescent head that takes a little fitting and doesn't have Colt contours exactly. Or a housing and rod for $75 that screws right on. The housing has an offset slot that keeps the head from rubbing down the barrel when used, however, it does not match the factory housing and is a little fatter; I didn't like it. Both available from Brownells.
My ultimate solution was an actual Colt rod from Brownells at about $35. For large calibers it's a drop in. For .22 and .32 single six frames you'll have to drill the hole in the frame slightly larger or thin the rod. I chose to thin the rod by unscrewing the head and chucking it in a power drill or drill press and using croakus cloth like a shoe shine rag. I pointed the end while I was at it so it can find the chamber mouth easier.
On the head end, it's a little longer than the Ruger rod which is good. It allows you to grind (with a dremel tool) a concave groove in the end of the rod to mate up with the ejector housing screw. It you align your concave cut with the ejector rod head held in a tight position against the barrel, you will achieve a slight cammimg action that will tuck the head up close to the barrel when released. A classy little touch and benefit when holstering the gun.
The 5" housing is an excellent choice with barrels over 4 5/8". I used one on a 5 1/2" 44 Mag Blackhawk and it pushed those long cases all the way out. It looks great too because it's even with the end of the barrel. Drilling and tapping the blind hole was and is simple if you've had experience. If not the cost of a gunsmith is worth the benefit.
Hope that helps,