Where do I get Secret Base items from?

Question

Is there like a store or are the decorations scattered around? Also how do I get trainers into my base and can I customize them? Where do I get the little paintings of Kyogre, Groundon, and Rayquazza?

Answer 1

Secret Base Guild:
In the south-east of town is the Secret Base Guild. Inside, you will find Aarune who will give you tips on your Super Secret Base as well as check flags and offer a variety of items to purchase.

You can get it in Fortree city.

EDIT: there more!

>First, in the west there is a small market which sells a variety of items.

Slateport will sell dolls, mats and ordaments.

It contains a massive PokéMart and a variety of other places.

Lillycove have a department store, if you go into it on the 5th floor, they sell a variety of stuff.

Peltalburg has plants that you can bye for the base, also!

Thanks for this: http://pokemondb.net/pokebase/116689/what-are-all-the-shops-that-sell-secret-base-items-in-hoenn