Hey caalie,
Welcome back to the forum 
! Good to see you again and thanks for your question.
There are a wide variety of wood platform beds and manufacturers will have specific recommendations on which would best serve their mattresses as well as which would void a product warranty. A 12" all latex bed is quite heavy, depending on its size, so its weight plus the combined weight of the users should be a consideration for how much the platform will support correctly. The type slats as well as slat spacing must be noted too; generally speaking, the slat spacing should be no greater than 3" apart and in some cases are recommended to be even closer. Sprung slats have some flexibility to them and “give” with the users’ weight, creating a softer feel to the mattress.A platform bed using a solid surface or bunkie boards makes a nice choice for sleepers preferring a firmer feeling mattress. For queen and king size mattresses, it is preferable to have a center rail with 2-3 supporting legs if possible.
What brand mattress is your 12" king latex? How long were you using it with the recommended metal wire base? A quick review of its warranty details will specify what type platform is appropriate to use, so be sure and check that before making your selection. Platform beds are discussed quite a bit on the forum, you may try a site search using “wooden platform bed” and see what that yields. Also, this recent post about Thuma and several other platform beds comes to mind. Hope this helps to get you started and perhaps other consumers will chime in with their thoughts… 
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Sensei