Creating a multi-touch funnel for a SaaS start-up. What CRM and stack we can use?

Hi all!

We are currently building our tech infrastructure for our planned sales funnel, selling SaaS subscriptions with 10k+ ARR ticket sizes to B2B clients. We have 2 SDRs and me as the sales guy.

What we envision:

1. Prospecting via either Apollo or LinkedIn Sales Navigator, picking a few hundred potential customers a month.
2. Putting those leads into a CRM.
3. Visiting the profile of the potential customer from multiple employee's start-up accounts.
4. SDR sending out a contact request with semi-personalized (AI?) message.
5. If accepted but not replied, send out follow-up on LinkedIn
6. If not accepted, send out mail
7. Follow up mail if no reply after a while, then another follow-up, then moving them to a bi-weekly value newsletter

Does it make sense for you and do you professionals think that this is a reasonable approach? If yes, which tech stack would you recommend? We struggle most with finding a good CRM.. none of them seem to tick all the boxes or come at a biiig price. We are bootstrapped, so limited budget

Obviously we'd love to automate most, but if feels like it most of it needs to be done manually.

Thanks for your input!