Welcome to the forum antipackers12.
A Chinese made aluminium boat will be of unknown quality, and you haven't even put an engine on it yet, rigged it, sourced trailer, etc. My advice would be to avoid.
Back to the Searider. There are plenty members on here (UK based and State-side) with years of experience. Get pictures posted, and plenty of them.
A full retube isn't going to be cheap. More details here on the process involved: http://www.dinghydoc.net/ribrepair.pdf
The Searider that's for sale, what's the condition, does it have an engine, history, trailer, documentation? Is the hull sound or is it rotten to the core? Post up as much information as possible and other members can point you in the right direction and give you a ballpark figure regards value.
Regards other boats, then get onto Craig's List and start scouring ads. You'll probably have to travel, but for the right boat, it's worth it. Also consider alternatives.