A 3S/BLX would mean upgrading to LIPO batteries and a LIPO compatible charger, as well as a fire safe charging bag. Going 3S also means a much, much faster truck, which can also translate to more broken parts depending on driving style. My recommendation would be either the Arrma Typhon Mega:
https://www.horizonhobby.com/produc...shed-4wd-speed-buggy-rtr-green/ARA102694.html
The Arrma Senton Mega:
https://www.horizonhobby.com/produc...brushed-short-course-truck-rtr/ARA4203V3.html
Or the Arrma Granite Mega:
https://www.horizonhobby.com/produc...-550-brushed-monster-truck-rtr/ARA4202V3.html
The reason i recommend the Mega over the BLX trucks are because, not only are they a bit slower, which means more controllable, to give you a chance to get used to them (they handle a bit differently, and are faster, than the Granite Voltage), they also run on NIMH or LIPO, so you dont have to spend the money on a 3S truck and needed battery, charger, fire safe bag, plus the learning curve that come with LIPO's all at once, they can be upgraded to brushless and LIPO's as you get more comfortable with them, and they are just as durable as the 3S/BLX trucks. Of the three though, the Granite is the one i would least recommend, since they are the quickest to traction roll, and are upside down a lot more than the other two (i hate constantly having to chase trucks to put them on their wheels, so that is mostly a personal thing with me). The shorter wheel base of a monster truck can, depending on where you run it, be a help or a hindrance. With the Senton, if you want the monster truck look, without the downsides of an actual monster truck, you can swap to monster truck tires, and raise the body up. The Senton is bigger than the Granite though, so in rough, tight terrain, especially with lots of trees, can get stuck easier, due to wider turning radius, and overall length and width. The Typhon is like any other buggy, they handle decent, and are much more controllable than a monster truck, but, sit lower to the ground, so they can get hung up a little easier if the terrain is rough enough, and putting monster truck tires on a buggy makes it look odd. Truggy tires and wheels, depending on the style, can work to raise it up a bit, but even those can look odd on a buggy. The Big Rock is like any other monster truck, in that it traction rolls easier, but, is also on the Arrma LWB chassis, so it is the same length as the Typhon/Senton, so it has some of the same downsides as the other Arrma LWB vehicles, with the wider turning radius, and the wider/longer body, but the wheels are skinnier than the Granite, which can be a hindrance. Going from a 20MPH Granite Voltage to a 50+MPH BRCC or Typhon is a huge jump if you arent used to it.