You are basically looking at a ThinkPad T series laptop. However, customizing it to your liking may push it over your budget. Also, I am do not know how bright the screens are, but since they all have anti-glare screens (with the exception of touch screen option) they should be fine to use outdoors based my on experience with laptops that have anti-glare screens with 250 nits to 300 nits of brightness.
http
/shop.lenovo.com/us/en/laptops/thinkpad/t-series/t560/
http
/shop.lenovo.com/us/en/laptops/thinkpad/t-series/t460/
The ThinkPad T560 is a 15.6" laptop with a base price of $809 and it comes with a dual core i5-6200u and 4GB of RAM. Upgrading to the i7-6500u is a $240 option. Upgrading to Windows 10 Pro is $30. Upgrading to a 1920x1080 screen will cost you $50. Upgrading RAM to 8GB is $70 and delays shipping by 4- 5 weeks so I suggest you purchase the RAM (which is going to cost less than $70) and install it yourself.
The T560 comes with two batteries which Lenovo refers to as "Power Bridge". It has an internal "front" 44Whr battery that is user replaceable, but you will need to open up the laptop to do so. The rear battery is removable and you have 3 options. The standard battery is 23.2Whr, but you can upgrade to a 47Whr battery for $5 or a 72Whr battery for $15. The Power Bridge technology works by using the external battery first, once it is drained it will then switch to the internal battery. If you have a spare battery, this means you can swap out the external battery with the spare battery (sold separately) without the need to turn off the laptop. I have not read any professional reviews of the T560 (or the 14" T460) so I do not know what the actual battery life under "normal" usage is with the various configurations.
Lenovo claims up to 24 hours of battery when using a spare battery. I assume that means you select the option for the 72Whr battery and purchase another 72Whr battery (probably will cost you at least $125).
The T460 basically a 14" version of the T560 for the same price of $809. However, there is one big difference other than the size of the screen. It only comes with a Core i3-6100u so you need to pay $70 for the Core i5 and $270 for the Core i7 CPU.
There are also the T460p ($935) and T460s ($980) variants. The T460p has a quad core i5-6440HQ CPU with the slightly more powerful Intel HD 530 graphics core rather than the Intel HD 520. A dedicated nVidia 940mx is optional for $80. Like the T560, it only comes with 4GB of RAM. However, a 1920x1080 screen is standard. But... it lacks Power Bridge so there is only a 47Whr or 72Whr rear battery. And you need to upgrade to Win 10 Pro.
http
/shop.lenovo.com/us/en/laptops/thinkpad/t-series/t460p/
The T460s is the ultrabook version it comes standard with the i5-6200u and a 1920x1080 screen. You will need to upgrade the RAM (the 4GB it comes with is integrated). Instead of coming with a 500GB hard drive that is standard in the other laptops, this has a 128GB SSD. It has Power Bridge, but the internal battery is 23.5Whr and the rear battery is 26Whr. You will need to upgrade to Win 10 Pro.