What is the best CMS for wholesale int. store, under 1s UT 8.3?

Question

CMS

In general, the management set the task of introducing a wholesale online store.
Now there is a site on opencart, but it is used as a catalog with pictures and company contacts.
It is necessary that the buyer be able to see the balance of goods, place an order and we can see it in our accounting system 1C UT 8.3. Make a little automation
Functionality for the beginning requires the most standard. Visually it will be similar to a retail online store - with a catalog and a basket and a personal account (orders, order status)
The number of articles will not exceed 300, the catalog is updated once a month. The volume of orders is not more than 30 per day.
Which CMS is more suitable for comfortable integration with 1C UT 8.3?
Budget up to 100-150k. It is important that the decision was for growth, so we decided to overpay.
Guess Umi, Magento, Bitrix to a lesser extent