Install fully functional 16gb ram on my MacBook model 7,1?

Wording is everything ;-}

A good salesman tries to imprint into your mind their product is better than someone else's. So the wording of OWC is somewhat ingenious here.

So heres the real poop:

First you do need to have the newest EFI firmware installed. Follow this Apple T/N: EFI and SMC firmware updates for Intel-based Macs.

Next you do need to get the correct memory modules: PC8500 DDR3 1066MHz 204 Pin and you do need to get two (2) 8 GB modules which also need to be a matched pair.

As to who's you get I would stick to one of the major memory houses and look at the pricing.

Even still I have found a few systems which should work don't. I suspect the clocking of the CPU and the Platform Controller Hub chip could be the factor. I've even taken out the modules of a working system and still find the system still won't handle 16 GB. Or, its possible the revision of the Platform Controller Hub chip was the factor. I never had time enough to make a deep study of it.

One last point the size of the chips and the number of chips (memory chips) on the memory module can also play a role in the cost. The older modules which have chunkier chips and have more chips will be cheaper. The newer slimmer chips and fewer chips (denser) will be more expensive.