Hard top bed covers ?

[Ttedeyan]

Hi I'm new to the forum and I was wondering members advice on hard top bedcovers. I've been looking at several and narrowed down to retrax and the peragon aluminum bed covers, I think. I like that both do not obstruct back window when open. I like the idea of the no canister with peragon and also the cost difference I found great here on this page https://truckpowerup.com/best-tonneau-cover-for-silverado/, but have some questions.
1.)How much space between the bed floor and a folded up peragon is there? How wide is this from back of cab bed towards tailgate? I'm wondering because it looks like if something slides towards back of cab you might not be able to open the peragon.
2.) if the peragon cover is wet, how do you keep water from draining into bed when opening? Is this much of an issue?
3.) can you put any weight on either peragon or retrax?
4.) can you put load bars over the covers, i.e. Thule with some adapter in the stark holes OR bed ladder/cargo rack?
Oh, I have a black 2012 Chevy 4wd crew cab. I'm looking to keep a few tools, containers with paperwork (flyers, promotional info), etc out of the cab and secure since I travel and want to keep thing neat and clean, also something easy to remove if needed to carry larger items.

Edited October 3, 2020 by Ttedeyan

[Sparty577]

I have the Peragon cover on my old f150 and just purchased another for my new at4.  The reason I chose it over the retrax was price and the fact that the Peragon allows me to use my TracRac SR rack.   I don't have the requested measurements at the moment, but it is easy to install and remove if you need to use the full need.  There can potentially be an issue if contents slide back, but I've never really had an issue and my bed is usually packed with tools, boxes, etc.  Once I get the new cover and last rack installed, I'll post some pics.  Note- if you look at the Peragon site, my black f150 is shown with the TracRac system.