If you are going to use deutsch terminals, go with closed barrel. Cheap crimpers are like $30 but they only do one of the 3 common size terminals. A good crimper that does all sizes can be had for around $150-200. I use the Jready DT2 but there are tons of other knock offs of the original Deutsch crimper.
There are 3 common connector types and contact size.
SZ20 contacts are used in DTM connectors and are small. They are rated for 7.5 amps and are a great choice for just about anything inside your jeep. Way smaller than a weatherpack connector, I use these the most but the largest wire you can use is 18awg.
SZ16 is the most common size and is used in DT style connectors.
SZ12 is for DTP style connectors and are for higher current. There aren't many places on a jeep i would use this size.
I also do not recommend buying those kits. It is way cheaper to buy the pins, sleeves, wedgelocks, and connectors in bulk from Mouser. However, over the past year these have been tough to get a hold of as they have had large backorders. I have spent significantly more money than i normally would because the only thing available was a "kit", which is both connectors, both wedgelocks, and pins and sleeves for that connector set.
Amphenol also makes these connectors and they are marketed as ATM, AT, and ATP.
I dont think there is anything wrong with weatherpacks, I just do not even consider it an option for anything over a 3 pin connector.