There are several other variants actually and you can decide to build it following the schematic online or just buy a fully assembled device, you can have it with input protection or color display...
The best is the one that better fit your need.
Yes, I hate when someone use this sentence... If I knew my needs I was not writing on a forum...
Seriously, to keep it simple, the first 3 you linked are the same. I choose the one with the case, as for me it worth it and the entire unit is very nice.
The last one is just an old version with 2 row LCD (I don't like this).
All the above are DIY but really easy to put together and all the components are really easy to replace (also the microcontroller) that you will easily destroy with a not discharged cap
BTW you can add input protection.
The remaining one is fully assembled, all the parts are SMD but it do not have the encoded that is nice to have to easily navigate trough the menus.
Again it is up to you to decide, but i'm really happy with this:
http://www.banggood.com/DIY-M12864-Graphics-Version-Transistor-Tester-Kit-LCR-ESR-PWM-With-Case-p-997023.htmlMauro