Ben, I use a MXS 5.0 and have found it to be excellent. In particular, I like the battery conditioner mode. After many years of use, I have zero complaints.

One thing to watch is the price does vary drastically - I've bought my two via Amazon and found the prices swings by +/- £20. A site like CamelCamelCamel UK will give a good bench mark as to price trends and will alert you when the price drops to a level you are comfortable with.

In terms of connection, I've tended to use these, direct to the battery, as John mentioned:

https://amzn.eu/d/a63WuVp

The indicator one is pretty basic, with the traffic light system but does help a little if you don't want to plug your car in each time you use it and just want a simple visual reference as to if you need to charge it or not. You can, should you prefer, get one without the indicator:

https://amzn.eu/d/hAMEZrl