With the SL30 you can do approaches to most airport, but the problems come in when trying to find fixes to some approaches and also the missed approach points. With the 430 you can use if for NDB point location as well as DME measurements.
I struggled with the same issues that your are looking into currently.
I started out with the idea of doing a VFR pannel. Then I disided to add the SL30 so that I could stay current with my IFR ticked. Now I could fly IFR if there were no clouds and I had a safty pilot, but to do real IFR I needed more. So I added the 430 and back up instruments for the EFIS unit.
But now I have alot of electrical equipment and if the alt. failed I would be screwed. So I added a back alt.
I sure hope that I will fly some IFR so that the expense will be justifyed.
I sill would like to add the 396/496 so that I could get the graphic weather info. I seen the unit and it would be real nice (VFR or IFR).
Although trying to diside on the panel setup was one of the hardest on my plane, the good thing about us expermental builds is that all it takes to change our panels is time and money.
Kent