Not at a premium price imho. The latest and greatest always cost more....they are slightly more efficient, as far as better results I believe the jury is still out on that.
Most larger seed suppliers are fine for most stuff. I use Seedsman because they carry other breeders along with their white label stuff. If your new to growing I suggest not buying the most expensive beans to start with....your probably going to kill a few...we all have.
Looks good for what your working with. You need around 100w to get any decent yield. Look for full spectrum light...should have 3000k, 5000k, and 660nm diodes at least...some now come with ir and uva included. Looks like your in an enclosed area so ventilation should be addressed also. Good luck!
There are 2 ways to go about it...sterile or beneficial bacteria. The above mentioned thread has excellent advice on sterile. I run Hydroguard but I have an aquarium chiller on my rez and keep temps 65 to 69f.
If you have bad smells you have a bad bacterial infection and choices are to clean and...
I run a 50/50 mix of OF and HF with 30% perlite added. Like others have said the first 3 to 4 weeks will need nothing except maybe calmag depending on your water source.
I'm assuming your a new grower so I would suggest if after the 4 weeks you feel the need to add nutes(depending on your light...