Trying different combo's for a pair of kingsized beds.  Need 2 beds anyway so I have 2 chances to get it right (the other will be a frequently used spare bedroom).

 I have FBM latex 6" core and 4 seperate 1" toppers of diff softness to change around. 

Some here have said they prefer the latex over a coil springs.  Since I can't take that back, or exchange it like the latex, does anyone have a suggestion for a good, well made, firm coil springs to serve as the base. 

Cost effective is important, but not the top priority.  So far Original Mattress Factory has their best for just under $700 with tax and delivery, but I don't know If I need that good since it will have 4" of latex over it.

I assume those that want the coils over the latex base do so for the added firmness of the coils anyway, but what do I know?