Need SEO keyword research for a large project

I am a copywriter working with a client in the USA who has an eCommerce selling tiles and stone. Like a Topps Tiles place.

My team is going to create lots of pages for the various categories on the site, but first I need someone to find the best keywords for EACH of those pages to rank for so proper SEO research is needed, so that we optimise each page and the metas etc.

I'd need one main KW, keyword variations and a few sugested LSI KWs for each page. Also for each page I need 3-5 commonly asked questions in that category, not random ones but ones that are actually being searched for to boost the SEO of the page.

I can give access to the client's analytics/search console for the chosen SEO, and I also have a full sitemap of pages required I can give you.

Pages would be like:
'ceramic tiles'
'commercial vinyl tiles'
'green porcelain tiles'
'mosaic limestone tiles'

1400 pages in total

This would just be an initial one off until the SEO content is written, then the plan is to handover the SEO guy to the client to collaborate on monitoring SEO progress ongoing.

Budget for this work is £1250 and the deadline to complete all of the keyword research is Monday 26th June.