Is the Iphone 4S 8G the only one that's going to be on the market?

I have a 4 but it's a little messed up so I want to upgrade. I'm eligible for an upgrade. I can see that the 4S will be a free upgrade but only for the 8G. Is that correct? 16G is not going to be on the market for the 4S? 8GB is too small for me but I'd rather not spend the money on a 5S or 5C if I can avoid it.

As far as I have seen it only seems to be the 4S 8GB, but I could be wrong. If that is the case you could always search up on Gumtree or Ebay for a 16 or 32GB 4S phone. You can also get some good deals on ebay as well and they are not so expensive on ebay either so you may also get one cheaper. Just always remember to read into it before you go rushing in. My partner got a phone off ebay and so did my friend and they were absolutely fine and fully functionable as well. So maybe just give it a shot:-)

The iPhone 4S is still available in the 8GB version.

Other versions were discontinued.

Yup. The 4S is only now available in 8GB.