Hello, !
What you want is silence and remote shutter support. In all honesty a used K5/K30 should cost a very low price (apparently you don't have that much money for now) and would do what you want. Because they are already at a quite low price, you could resell them again without loosing too much in 1-2 years.
The K5-IIs is going to loose more value... and is still not the final objective that the K3 is. This allow you to cencentrate more on the lenses you want.
The things you are going to miss compared to K5-IIs is just better AF in low light. To K3 you add much better AF in all conditions and more crop capabilities. Couting you have good enough lenses.
For know still, a used K5/K30 for a small price is better for your case