Am looking to setup a simple "interface" program. Nothing complex and hopefully using open source or even another program that allows me to change the interface and apply our branding

The goal is to consolidate multiple programs into one user friendly interface so users can just click on what they want to start (in some cases that would launch a website in other cases an executable)

If for some reason the software isn't present they just get a simple
"I'm sorry you don't have that feature" is displayed then an option to be directed to the website where that feature is marketed or sold

An options menu where they can add the links if they later purchase the software

Again nothing crazy complicated. Professional gui that simply points to other programs and websites
Making it easier for the customer so they can use one program to access many