Should I connect Stripe or PayPal to take payments?

Use Stripe. PayPal is not as professional an experience, and Stripe is free to open. You need a connected Stripe account to publish your SaaS plan and take payments. Until then the plan stays a draft.

If Stripe gives you trouble when signing up, you can have more than one Stripe account (many people have several businesses), so create a new one with a different email address. Do not sign up through a VPN, because Stripe is sensitive to that.