I've had one of these for a couple of seasons. It replaced a similar two cycle Stihl that I used for twenty plus years. We live on forty plus acres in the PNW and everything grows at a prodigious rate.
The 131 will support various saw, mulching, and hacking blades that add a tremendous amount of versatility to the system. It will cut saplings up to about three inches and you can hack your way through blackberry patches the size of a two car garage and as tall as the operator.
@AngryKoala I know you bought a battery powered and 58V sounds like it should go all day. If you should decide you need more a 131 will go as long as you can and that's brush cutting not weed eating. If you can go ten hours it will still be cutting.
If you are going to use a weed-eater for brush cutting you need the handle bar/bicycle grip. If you somehow get dirt in your gas-can just throw the contents out and send the can after it. Use only ethanol free fuel. I add a little "Sea Foam" to even ethanol free. The advice to lube the drive head is good advice. Stihl has a small tube that threads into the head when you remove the screw. Don't thread it tight to the head. You'll being trying to get grease into an airtight space and that won't work.
What chain saw? A Stihl 044 of course.
Here are a couple of other general recommendations. Big chain saws are a two sided coin. They can get a huge amount of work done quickly. They are also heavy and powerful and can turn on you like a trapped bobcat. If you know a logger, with experience as a faller, impose on him for some advice. Not only on how to handle and maintain your saw but also have him walk your place looking at trees with you and advising you on how he would fall big trees and why. When buying a saw, brush cutter/weed eater, it's best to figure the biggest you'll need and then buy the next one up. Don't make mistakes. Logging is an extremely hazardous job. The pros are usually in the woods with other pros. Everybody has radios and should know where almost everyone on the show is if anywhere near.
If you're out there alone on your place you're.....well......out there alone.