I don't think either tool would be suitable, especially if you don't have any experience doing bodywork.
The first one needs a fairly large reasonably flat area to attach itself to and given the way the metal is caved in you might end up pulling at the wrong point. The slide hammer needs the 'nails' welding to the metal so unless you have the tools for that, it's not going to do the job for you. Especially with the slide hammer, you also will need paintwork afterwards and might even have to weld closed a few holes if the 'nail' rips off during slide hammer use, as that tends to leave a hole behind. With the first one you have a better chance to not do any further damage if you can get it to adhere to the metal and pull carefully - you don't want to go from pushed in to pulled out...
What I would probably do (caveat: I have done bodywork before) is try to see if I can get to the dents from inside the car. If you can, warm up the outside of the car with a fan heater or a hair dryer (the latter on low heat) so the paint softens a little and becomes less brittle. Do that very carefully, then see if you can pop out the dent from the inside with your hand by just pushing it out. To be honest, given the depth of the dent the metal might have stretched enough that you can't just pop out the dent without shrinking the metal.
I would check if there is a paintless dent removal service in your area and have a word with them if they can fix the dent cheaper than the bodyshop who gave you a quote.