The Delta unit in your first link is a good dust collector FOR A SINGLE MACHINE. If you are willing to move the collector from one machine to another as needed, this is a good deal.
If you want a collector you can connect to everything in your shop and not move around, you have a lot more work to do. The size you need depends on how many machines, what type of machines, duct length, size and type, how many machines you want to feed at once, etc. You have to design the whole system and do the airflow loss calculations before you will know how many CFM you will need.
A collector in the 1100 CFM or higher range (like the HF one you mentioned) will handle a couple of machines, and can probably fit your whole shop if you install the ducts and blast gates correctly. (Be sure to properly ground your ductwork so you don't blow up your shop!)
Dust collectors aren't exactly high-tech ... a blower and some sheet metal. The HF unit probably works pretty well.
If you can afford the extra cost, I would recommend looking at the "canister" style collectors. They do a much better job of filtering the fine dust (some dust blows right through the cloth filter bags), and the plastic dust bags on the bottom are a lot easier and cleaner to empty/replace.