It really depends on what size fish you want to weigh and the accuracy you expect. Digitals might suit you more since they aren't dependent on reading from a spring.
On water test kits, you may or may not need one. If you are in East Texas or pine tree country, you will have to monitor possibly scarce alkilinity to know whether to lime and fertilize. West Texas generally has enough alkilinity. For a start, I would send my water sample to A & M. They will tell you more than you can understand.
