If you are going off road, neither are a good choice. Both act up on steep inclines and tend to flood.
The Solex is a knock off. The jets are hard to find, and people with experience tuning hem are even harder to find. If you are going to go with a Weber, make absolutely sure it is a genuine Weber 32/36 or if you have a modified engine a Weber outlaw 38.
At this time the CV carbs are a very good way to go.
Before you ditch the stock carb, replace your PCV, replace all your vacuum lines, and check for somethign disconnected or dirty. If you get a ne carb, you'll have to tune it to your rig. Why not get that experience now, and possibly save your self the headache of a carb swap by getting yours running right. At least you will know ether or not your stock carb is shot.