Light fixtues

Last year was not very successful starting seedlings in the spring (and many other springs). Some did ok with our bright west-facing windows but most were leggy and didn't get a great start. I ordered a LED light off of amazon to supplement when starting my fall seeds. I really think it is fake because I still ended up with leggy seedlings running this light in addition to the natural light through the window and putting them outside in sun when I could (I live in the SE so this was difficult because sometimes it is just too hot for them). I ended up just buying fall plants from the garden center which did great and my terrible home-grown transplants really didn't amount to anything in the garden. I hate to rely on the stores because it's not very sustainable plus I like to have some of the odd varieties from baker creek, etc.
I really want to start some strong seedlings soon in January so I have some great plants to get started early - I think we will have a pretty mild winter and hoping to get some cool tolerant tomatoes in the garden in March with some other cool season stuff and then follow with better tomatoes, etc. in May. I am wondering what products/set ups others have found to be helpful. I don't want to take up too much space, as my garden is not that big, but I would like to be able to grow maybe 2-3 normal sized trays of plants at a time to handle the overlap in starting times/seasons - I don't think my cool season stuff will be ready to go out before I need to have summer stuff started, etc. I also want to be somewhat price conscious also. I don't know if it is cheaper to just purchase some fixtues/bulbs from home depot (I don't even know what kind of bulbs) and some type of cheap shelving unit or if it is just cheaper to purchase one of the pre-fab set ups from gardeners or one of those other suppliers. Any input is very appreciated. Thanks!

I'm thinking of installing a walk-in closet in my master bedroom. I would like to do this myself but I dont have too much hands on building experience, but I have a masters in architecture and understand the theory.
I would have to rip up carpeting and install two walls that come together at the corner with a door on one. I would hire someone to do the electrical because a light switch needs to be rewired and fixtues would need to be added. I would also have someone come in after to install new carpets.
Should I do this myself or should I hire a contractor for this tiny job?
Edit: I'm located in Santa Barbara CA

I'm a small time electrician and i have a client who has a little automotive body shop with 12 400 watt metal halide high bay fixtures about 20 feet off the floor and he is very interested in retrofitting them to led. My question is would a standard corn style retro lamp be fine or should i go with the specialty high bay retro lamps (at additional cost). also what wattages and kelvin would you recommend to get at least similar and possibly a little higher light on the floor. I will include a sample pic of the style light he has installed and two links for the lamps i am considering for installation. Thanks in advance everyone. retor bulb number 1 http://keystonetech.com/spec_sheets/KT-LED115HID-V-EX39-850-D.pdf ........ retro bulb number 2 http://keystonetech.com/spec_sheets/KT-LED100HID-EX39-840-D.pdf. currently installed fixtures https://www.zoro.com/lithonia-lighting-fixture-high-bay-400-w-thd-400s-a15-tb-lpi/i/G1681732/feature-product?gclid=CjwKCAjwsIbpBRBNEiwAZF8-z9zJsFrPOF5G15JjtMgWTj00APjJlGtC_ocDtqEhiXQ1N895tGas5BoC-tEQAvD_BwE