Acrylic skylights are not very effective at anything other than keeping out water. Thermally glass is much better, I would suggest using the glass and using the bronze tinted glass option. Vented would definitely help with air exchange as hot air rises and this would allow it to escape. Motorized with rain sensors are great but can get pricey. You may also want to get what they call "solar screens" which installs where screens go and it is a different type of mesh that still acts as a screen but with the added benefit of some sort of blocking for the heat gain. I personally think Velux is a very good skylight but having been in the business for years I never liked selling them because of their business model and I have always recommended regional manufacturers for that reason.