The new tool Tamiya Stug is a top notch Early G. This is probably the best kit on the market of a Stug III. But, it is definitely the Early G.
Don't waste your time on the earlier Tamiya offering.
If you want anything other than an Early G, then you need to go Dragon.
I personnally liked the Dragon Stugs. Their detail is not as crisp as Tamiya's. But, they are definitely buildable kits. Some will need attention from the aftermarket people (namely the tracks and the tool clasps). I'd defintely sit down with the Achtung Panzer on the Stug III for any of the Dragon ones and correct what needed to be done. I've seen many modelers with not a tremendous amount of effort turn the Dragon Stugs into show-winners.
And if you bought each one of the Dragon Stugs, you could litterally build the entire Stug III family.
That's just my 2 cents. I hope this helps.