Landing Pages with One Click Upsells & Order Bumps

I know I could do this on another platform or on my website, but I hate having different systems that confuse people (when they can't easily cancel). What I really want is to have all member subscriptions and payments in one place. Therefore, I'd really like the ability to design different landing pages, or at least have the ability to design one-click upsell funnels and order bumps at checkout. Also, if I had the ability to design better landing pages, then I could really utilise the affiliate functionality more as well.