I am looking for the French St Chamond tank. Both Hobby Boss and Takom make one. Any pros/cons between the two kits? Any heads up on any issues I need to be aware of?

I suggest Hobby Boss if you want to keep your sanity. Takom has multi-piece tracks.
Regarding accuracy, I am not sure.

This may help you:

Full review on Takom's
http://armorama.com/review/11370

What is in the box for Hobby Boss:
https://armorama.kitmaker.net/news/21532

If my experience after scratch building missing and wrong parts on all 4 of the Hobby Boss kits I have done is anything to go by, and based on the above review, if you want accuracy then acquire the Takom one.....

Honestly, as far as multi-piece tracks go these were pretty painless. get a good Xuron God Hands style sprue cutter to minimize cleanup and they go relatively quickly.

I've built the Takom but not the HobbyBoss. I really liked the Takom kit. Certainly the easiest individual link tracks I've ever encountered. They basically snap together.

Without doubt the HB kits. I have built Takom's early and HB late. A very big difference in detail and proportions. HB includes the complete gun and supports.

Can't speak to accuracy, but I built the HB mid version and it was rather easy. The tracks are single-piece links that simply click together! The only tricky spots are the suspension which is fragile until fully assembled) and the MG mounts (that are oddly fragile and not very firm in attachment points - I glued mine in place to ensure they were firm). I found the road wheels needed a spacer added to the axle to widen them by about 0.020" so the flanges fit around the raised bit of the track links - best to do this BEFORE you get it all assembled! (Ask how I learned...) My only gripe is that there are lots of big doors, but nothing to see inside!