Magento 2 migration from magento 1, with customazation work

Need expert in magento 1 and magnento 2. We need customazation and migration. The magento 1 is a marketplace site with five language sites, each lanugage with individual domain, but with same backend. Customazation major done in the vendor's account. We also need app for it in a later stage. We need clear price, with specific timeframe.

Previous work with good result will be appreciated if you can provide.