My recommendation,
Use non ghosting, No Flickering, super flux bulbs for the inserts..They are the best there is!
They are at Pinballcenter.eu as Super Flux, at $2.55
They are at Pinball decals for $3.55
and at Comet Pinball at $1.99
For your GI, Use Frosted Natural Whites. Mix in some Blues, maybe some purples, a few warms, no worries about having an extra 10 bulbs to rearrange as you need.
These are found almost everywhere from $.59-$1.29