I built my own front rest, but there are many good ones out there. Bald Eagle is a very good one as well as Hart. Sinclair sells them off and on. You want one that uses the common thread size for the post. I didn't, and have regretted this for as long as I've used my own. The windage plate is critical, and Sinclair sells several different models. Then there are several options to aid your shooting position. Once again I used the wrong thread size here as well.
When shopping for a front rest, check the lock up very closely. If you can still move the threaded post, then avoid it. Some guys used the front rest without it be clamped tight. Or others clamp it after sighting in the target. If there's movement you won't hit much of anything. I clamp mine lightly, and can actually raise or lower it. On the otherone I still use, you can't raise or lower it with anykind of clamping pressure due to the thread fit (extremely tight)
If you have access to a lathe, you can build one fairly easily. The hardest part if drilling and tapping for the legs. I've built at least a half dozen for myself, and maybe twelve altogether. Some were very crude, and others too high tech. It's a learning process.
gary