On the subject of power points: get more than you think you'll need. Costs a bit more but is way cheaper than adding them later. 15 amp is good, but consider at least one 32 amp. I bought my son a good MIG welder from BOC. It has a 15 amp plug fitted, but it turns out that was fro "demo" purposes. It needs 32 to run its duty cycle.
Splurge on good lights as well. Better to do it now during the build, if you can stretch the budget, cos you won't later. LED Highbay are pretty good.
Also, consider painting the floor. Doesn't sound like much, but it makes a huge difference for keeping it clean from oil spills, and the reflected light is really worth it.
Before and after:
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