If you would like to estimate the labor hours for your project you can use the MCA labor hour values. You already have the material, quantity, and size. All that you would do is multiply the quantity by the labor value, plus your mark-up to make money, and any straight time or overtime multiplier. If you really want to impress on your project and you have to fabricate your own material instead of have a vendor supply it then you can create a mini supply chain for yourself with competing pricing for labor in different labor markets. If you need hourly rates for pipe fitters and welders you can look on the Bureau of Labor Statistics website.
Your second question and what the first poster commented are usually covered in other line items for the estimate called general conditions. This category is fast and loose. For example, you will have a line item for QA/QC because you need someone to inspect and test the welds for project completion. You will have a line item for tools and rentals. You will need grinders and grinding wheels, you might want to laser line everything, or you may need to slope the pipe if it is a drain system. You will have a line item for Safety. This will include a Safety supervisor and PPE for guys in the field and any fab shops. If you are welding SS the guys will need respirators or vacuum systems for the dust/fumes. The first poster mentioned the schedule which you will have to create with input from your customer. Are they willing to pay for overtime? How much OT per week? How many people do you want to hire? How many tasks can your crew handle simultaneously? What is a reasonable amount for work for 2 people to complete, 4 people, or a team of 200 people, etc.
In terms of equipment you might consider portable welders, a man lift, crane, or forklift