For a startup, there are a fairly large number of CRM systems, and you need to know specifically what you are doing in order to suggest a specific option. Maybe you'd better make your own choice ?! Here on this resource https://apiway.ai/categories/crm-for-startups , there is a large selection of CRM systems designed specifically for startups. For a start, you can choose something cheaper, and then move on to more advanced CRM systems. It's my opinion.