IMO the SPAD is actually the same as the Eva Dry and is likely sufficient for your needs.
For your application it should be plenty capable as the SPAD has quite a lot of silica in it. If you find that the one you currently have is reaching capacity more frequently than you would prefer, you could add a second but I think one will be plenty capable here. My guess is that it should give you at least a month between needing to be recharged, and possibly longer.
Also, since the safe does not have fire protection and it is being opened frequently, this can also reduce the concern for humidity. The only exception would be if the location where you have installed the safe has extremely high humidity on a frequent or constant basis. If that is the case and the safe is left open for extended periods, you will need to recharge silica gel products on a more frequent basis.
In some cases, placing a material such as weatherstripping or silicone or polyurethane around the door jam and sealing off any openings such as a bolt holes can allow one to get the humidity to a super-super low level with the right product. I have a 2.5 cubic foot Stack On cabinet I use for ammo storage that I have done this with. Using an adhesive polyurethane strip to improve how air tight the safe is when closed, along with a silica gel product, I can keep its humidity even lower than I do in the safes I store firearms in. The main purpose of this is for maximizing the longevity of ammo that I plan to keep for decades (e.g., defensive loadings.)
I also remembered that Stack On has quite a few adhesive foam blocks designed to act as padded barrel rests. If that could potentially help you, they have great customer service and I would not be surprised if you called them and they sent you some for free to see if they help your needs.
I have moved to custom interiors since most safe rifle racks store all rifles at the same elevation (because if all rifles are stored at the same base height, the thickest part of the rifles will all meet in the same area, reducing total capacity and potentially increasing the chance of cosmetic damage.) By varying the base elevation by 6-10 inches, this staggers the rifles so they are no longer all meeting at the thickest point, increasing capacity while potentially reducing how much they bang into each other during storage.
