The first two names, PearlSlots.com and EldoradoSlots.com, are too game specific... does your casino only have slots?
PandaCasino.com is kind of cutesy, kind of fun, but not very glamorous or serious.
PearlCasino.com and EldoradoCasino.com are also both already taken.
PearlCasino.com resolves to Casino.net and EldoradoCasino.com is a land based operator in Henderson, Nevada. Therefore promoting an online casino under those two brand names would be confusing because a certain % of people trying to find you will likely type in the ____Casino.com version of the name assuming that is where they are going to find you, and they won't.
Anything that has the ____Casino.com or .com version of the name should be out of the question. So .net should only be registered to cover your branding not as your sole domain for business. Very few online casinos operate solely on a .net domain.
Also consider that if you pick up a ____Casino.com branded name, then you will most likely also want to pick up the ____Poker.com, ____Sportsbook.com, ____Bingo.com, ____Etc.com versions of the name too. Almost every major online gaming brand does this, and it's a wise choice to cover all variations even if there are no immediate plans to venture into one of these lines of business. It keeps the squatters at bay.
As for casino names, I have many. I've been involved in online gaming for 14 years. I've done work for most of the biggest brands online. I used to be the art director in Gibraltar for a major gaming brand and my girlfriend currently works for Party Gaming. I will send you a PM and if you would like to discuss further we can go from there.