WCAG level A and level AA + B2B + SEO Website Build

I need a new B2B website that immediately builds trust with visitors by showcasing in-depth case studies, client success stories, our company history, team values, certifications, awards, and a visual gallery of completed projects. The site must be fully optimised for search engines and meet WCAG 2.1 Level A and AA guidelines on every page so that business owners, senior decision-makers, procurement teams and technical project managers can access the content easily—regardless of device, browser or ability. Accessibility & SEO are non-negotiable. Every template, component and media asset must include proper semantic markup, ARIA roles, alt text, keyboard navigation, colour-contrast ratios and structured data so we rank well and comply with international accessibility standards. Clean information architecture, fast loading times and on-page optimisation (title tags, meta descriptions, schema, internal linking) are equally important. I am open to the CMS or static-site generator you recommend as long as it supports easy content editing, multilingual expansion and future scalability. Deliverables • Fully developed website ready for launch, with responsive layouts and WCAG 2.1 Level A/AA validation • SEO-optimised page templates (home, service overview, individual case study, about/company, certifications, gallery, contact) • Content migration of supplied text, images and PDFs, formatted for readability and accessibility • Technical documentation covering theme structure, plugins/modules used and instructions for adding new accessible content • Two rounds of revisions after the first complete build Acceptance criteria • All pages pass automated and manual WCAG 2.1 Level A/AA checks • Core Web Vitals in the “good” range on both mobile and desktop • Each URL scores green on lighthouse SEO audits (90+) • Site deployed to our hosting environment and verified in Google Search Console Please outline a realistic timeline, the toolkit you intend to use (e.g., WordPress + Gutenberg, Webflow, Jamstack, etc.) and a brief summary of similar WCAG-compliant B2B sites you have launched.