Wanted to update this thread with the latest update as I found both the information Philip and Carl provided to both be quite valuable.
Thank you both Philip and Carl!
So I tried Auto Slash per Carl ; had read something about them previously and seems a cool service.
They showed some great rates from Avis booked through Priceline. Much better rates than I had seen elsewhere and with Avis who is usually higher priced.
I booked and felt it uncomfortable they took nothing down on me of importance, no payment at all, no credit card, no DL or anything other than my email.
I felt like it was a great deal but had this fear in the back of my head that I could show up at the counter to bad news, a rare case where not provided a credit card or payment made me feel worse.
I have an Avis confirmation# but seemed odd they did not want anything from me to secure the reservation.
Auto Slash though did prove quite valuable and it is not their fault Priceline didn't want a credit card or any type of payment guarantee from me. I will use Auto Slash in the future, especially for US rentals where I am more comfortable with the whole process due to no language barriers and unfamilarities.
So with that fear in mind I tried what Philip said and went to Auto Europe.eu
No clue why but the rates for Lisbon where much better than on the .com site
Rates I could stomach and much different for both Compact and Midsize cars.
So I booked with Auto Europe.eu a Europcar and then went to Priceline and cancelled my Avis reservation.
The Avis through Priceline rate was less expensive for same car class, about 40 euro less! But since I was comfortable with the cost and been happy with Auto Europe when I have used them previously I decided to go that route.
Hopefully my loyalty to using them does not bite me back by using their EU site.
Interesting, I plugged my already booked dates for Nice, France into Auto Europe.eu and the rates are actually higher than those on Auto Europe.com for both car types ; so EU is not always cheaper.
Car is now booked, problem solved and Thank You to all who responded. Some good info in this thread
Hopefully no downside to using the .eu site for USA based address customers ; but I will over the next few months occasionally check both sites to see if either rates drop.
They both are fully cancellable without charge.