Creating your own landing page can be a challenge. Because they're so conversion-focused, getting something wrong is super easy. My recommendation is to look into the many landing page template providers out there - something that's already designed by UX experts and professional designers. A good landing page builder (like Wishpond) makes something which can be overwhelming and complicated quick and easy.
ClickFunnels limits your access to certain types of pages and funnels based on your account level(ClickFunnels pricing of $97+ gets you all the access), but you get full split testing capabilities. The problem with Leadpages Pricing is that you don't get split testing capabilities at their startup price point. This is not good, nor something you want to miss out on. You have to split test as a marketer or you are flying blind. I explain more in this post on split testing.
The Actionetics email builder also comes with an Action Funnels feature which allows you to hyper-segment your contracts in order to trigger external and internal actions at the appropriate time. Internal actions may include, for example, being removed/added from an email list, which external actions may include things such as being able to receive email sequences.
Prospecting and marketing are all the things you do to get people into the first of your sales funnel stages. Note that stages are broken into two or more steps wherever possible. A demo could be called a single stage, but in real life it involves a lot of things: contacting the customer, sending reminders, doing the demo, and then following up. Whatever your own sales stages look like, the support you need in managing them will be the same.