I have not seen windlasses sold as 'systems'. Usually, you will get the windlass, the main circuit breaker and the solenoid. So you will have to get the power cabling, helm switch, and perhaps an additional circuit breaker for the control cabling.
You will also need a bow roller, some chain that is compatible with the windlass 'gypsy' and then some rode (anchor line) that is also compatible with the gypsy. You will need a 'swivel' to go between the anchor and the chain to take out any twist in the rode. Most windlasses work best with braided rode, not the 3 strand twisted rode that many smaller boats have. You may also need a new anchor to work best with the anchor roller.
Maxwell and Lewmar are good choices. There are a few others. You will have to decide on a 'horizontal' or a 'vertical' windlass. Vertical looks cleaner in terms of deck machinery.
I installed a Maxwell RC8-6 windlass on my 33 foot Formula . . . it is a bit under powered for the size of boat, but probably would be good for a boat in the 25-28 foot range.
I did the installation in 2 steps . . . first the bowroller and anchor set-up, plus roughing in the wiring. Then (the next year) I installed the windlass, circuit breakers, and switch panel, rode, etc. Here is a link to my thread on the project:
https://forums.iboats.com/forum/gen...gine-topics/9869521-new-anchor-and-bow-roller
Plan on spending about $2500-$3K for everything you will need.